31138216811520 has 1056 divisors, whose sum is σ = 127810370753856. Its totient is φ = 6409499443200.

The previous prime is 31138216811509. The next prime is 31138216811521. The reversal of 31138216811520 is 2511861283113.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31138216811521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 401118310 + ... + 401195930.

Almost surely, 2^{31138216811520} is an apocalyptic number.

31138216811520 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 31138216811520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63905185376928).

31138216811520 is an abundant number, since it is smaller than the sum of its proper divisors (96672153942336).

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

31138216811520 is a wasteful number, since it uses less digits than its factorization.

31138216811520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77717 (or 77692 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 42.

The spelling of 31138216811520 in words is "thirty-one trillion, one hundred thirty-eight billion, two hundred sixteen million, eight hundred eleven thousand, five hundred twenty".