400288129920 has 1536 divisors, whose sum is σ = 1709147381760. Its totient is φ = 84403814400.

The previous prime is 400288129919. The next prime is 400288129921. The reversal of 400288129920 is 29921882004.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (400288129919) and next prime (400288129921).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400288129921) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 3741010507 + ... + 3741010613.

It is an arithmetic number, because the mean of its divisors is an integer number (1112726160).

Almost surely, 2^400288129920 is an apocalyptic number.

400288129920 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 400288129920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (854573690880).

400288129920 is an abundant number, since it is smaller than the sum of its proper divisors (1308859251840).

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

400288129920 is a wasteful number, since it uses less digits than its factorization.

400288129920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284 (or 269 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The spelling of 400288129920 in words is "four hundred billion, two hundred eighty-eight million, one hundred twenty-nine thousand, nine hundred twenty".