31861815040 has 288 divisors, whose sum is σ = 86318447040. Its totient is φ = 11167334400.

The previous prime is 31861815001. The next prime is 31861815043. The reversal of 31861815040 is 4051816813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31861815043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 55995876 + ... + 55996444.

It is an arithmetic number, because the mean of its divisors is an integer number (299716830).

Almost surely, 2^31861815040 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31861815040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43159223520).

31861815040 is an abundant number, since it is smaller than the sum of its proper divisors (54456632000).

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

31861815040 is a wasteful number, since it uses less digits than its factorization.

31861815040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 739 (or 725 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 37.

The spelling of 31861815040 in words is "thirty-one billion, eight hundred sixty-one million, eight hundred fifteen thousand, forty".