400245021520 has 20 divisors (see below), whose sum is σ = 930569675220. Its totient is φ = 160098008576.

The previous prime is 400245021503. The next prime is 400245021529. The reversal of 400245021520 is 25120542004.

It can be written as a sum of positive squares in 2 ways, for example, as 274379011344 + 125866010176 = 523812^2 + 354776^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×400245021520² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400245021529) 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 3 ways as a sum of consecutive naturals, for example, 2501531305 + ... + 2501531464.

It is an arithmetic number, because the mean of its divisors is an integer number (46528483761).

Almost surely, 2^400245021520 is an apocalyptic number.

400245021520 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400245021520 is an abundant number, since it is smaller than the sum of its proper divisors (530324653700).

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

400245021520 is a wasteful number, since it uses less digits than its factorization.

400245021520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5003062782 (or 5003062776 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 25.

Adding to 400245021520 its reverse (25120542004), we get a palindrome (425365563524).

The spelling of 400245021520 in words is "four hundred billion, two hundred forty-five million, twenty-one thousand, five hundred twenty".