400135680 has 320 divisors, whose sum is σ = 1626324480. Its totient is φ = 91348992.

The previous prime is 400135667. The next prime is 400135691. The reversal of 400135680 is 86531004.

It is a tau number, because it is divible by the number of its divisors (320).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 483427 + ... + 484253.

It is an arithmetic number, because the mean of its divisors is an integer number (5082264).

Almost surely, 2^400135680 is an apocalyptic number.

400135680 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 400135680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (813162240).

400135680 is an abundant number, since it is smaller than the sum of its proper divisors (1226188800).

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

400135680 is an equidigital number, since it uses as much as digits as its factorization.

400135680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 866 (or 844 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 400135680 is about 20003.3917124072. The cubic root of 400135680 is about 736.8895985428.

Adding to 400135680 its reverse (86531004), we get a palindrome (486666684).

The spelling of 400135680 in words is "four hundred million, one hundred thirty-five thousand, six hundred eighty".