400135332520 has 128 divisors (see below), whose sum is σ = 1123946876160. Its totient is φ = 124552028160.

The previous prime is 400135332427. The next prime is 400135332521. The reversal of 400135332520 is 25233531004.

It is a super-4 number, since 4×400135332520⁴ (a number of 48 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is not an unprimeable number, because it can be changed into a prime (400135332521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2245752 + ... + 2417368.

It is an arithmetic number, because the mean of its divisors is an integer number (8780834970).

Almost surely, 2^400135332520 is an apocalyptic number.

400135332520 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 400135332520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (561973438080).

400135332520 is an abundant number, since it is smaller than the sum of its proper divisors (723811543640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

400135332520 is a wasteful number, since it uses less digits than its factorization.

400135332520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172403 (or 172399 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 28.

Adding to 400135332520 its reverse (25233531004), we get a palindrome (425368863524).

It can be divided in two parts, 400135 and 332520, that added together give a triangular number (732655 = T₁₂₁₀).

The spelling of 400135332520 in words is "four hundred billion, one hundred thirty-five million, three hundred thirty-two thousand, five hundred twenty".