431561737728 has 400 divisors, whose sum is σ = 1453697649360. Its totient is φ = 126262886400.

The previous prime is 431561737709. The next prime is 431561737729. The reversal of 431561737728 is 827737165134.

431561737728 is a `hidden beast` number, since 4 + 3 + 1 + 561 + 7 + 3 + 7 + 72 + 8 = 666.

It is a super-2 number, since 2×431561737728² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (431561737729) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 13213258 + ... + 13245878.

Almost surely, 2^431561737728 is an apocalyptic number.

431561737728 is a gapful number since it is divisible by the number (48) 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 431561737728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (726848824680).

431561737728 is an abundant number, since it is smaller than the sum of its proper divisors (1022135911632).

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

431561737728 is a wasteful number, since it uses less digits than its factorization.

431561737728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32691 (or 32666 counting only the distinct ones).

The product of its digits is 5927040, while the sum is 54.

The spelling of 431561737728 in words is "four hundred thirty-one billion, five hundred sixty-one million, seven hundred thirty-seven thousand, seven hundred twenty-eight".