31780661898040 has 32 divisors (see below), whose sum is σ = 78007079205360. Its totient is φ = 11556604326400.

The previous prime is 31780661898031. The next prime is 31780661898049. The reversal of 31780661898040 is 4089816608713.

It is an interprime number because it is at equal distance from previous prime (31780661898031) and next prime (31780661898049).

It is a self number, because there is not a number n which added to its sum of digits gives 31780661898040.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31780661898049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36114388081 + ... + 36114388960.

Almost surely, 2^{31780661898040} is an apocalyptic number.

It is an amenable number.

31780661898040 is an abundant number, since it is smaller than the sum of its proper divisors (46226417307320).

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

31780661898040 is a wasteful number, since it uses less digits than its factorization.

31780661898040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72228777063 (or 72228777059 counting only the distinct ones).

The product of its (nonzero) digits is 13934592, while the sum is 61.

The spelling of 31780661898040 in words is "thirty-one trillion, seven hundred eighty billion, six hundred sixty-one million, eight hundred ninety-eight thousand, forty".