31040023520 has 144 divisors (see below), whose sum is σ = 84110412960. Its totient is φ = 10796375040.

The previous prime is 31040023517. The next prime is 31040023537. The reversal of 31040023520 is 2532004013.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 31040023492 and 31040023501.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 410426 + ... + 480134.

It is an arithmetic number, because the mean of its divisors is an integer number (584100090).

Almost surely, 2^31040023520 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 31040023520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42055206480).

31040023520 is an abundant number, since it is smaller than the sum of its proper divisors (53070389440).

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

31040023520 is a wasteful number, since it uses less digits than its factorization.

31040023520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69769 (or 69750 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 20.

Adding to 31040023520 its reverse (2532004013), we get a palindrome (33572027533).

The spelling of 31040023520 in words is "thirty-one billion, forty million, twenty-three thousand, five hundred twenty".