31257642240 has 864 divisors, whose sum is σ = 124586542080. Its totient is φ = 7166361600.

The previous prime is 31257642223. The next prime is 31257642287. The reversal of 31257642240 is 4224675213.

31257642240 is a `hidden beast` number, since 3 + 1 + 2 + 5 + 7 + 642 + 2 + 4 + 0 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 31257642195 and 31257642204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 286767306 + ... + 286767414.

Almost surely, 2^31257642240 is an apocalyptic number.

31257642240 is a gapful number since it is divisible by the number (30) 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 31257642240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62293271040).

31257642240 is an abundant number, since it is smaller than the sum of its proper divisors (93328899840).

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

31257642240 is a wasteful number, since it uses less digits than its factorization.

31257642240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251 (or 234 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 36.

The spelling of 31257642240 in words is "thirty-one billion, two hundred fifty-seven million, six hundred forty-two thousand, two hundred forty".