21310031000 has 64 divisors (see below), whose sum is σ = 50026541760. Its totient is φ = 8496480000.

The previous prime is 21310030999. The next prime is 21310031023. The reversal of 21310031000 is 13001312.

It is a super-2 number, since 2×21310031000² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 276740 + ... + 345260.

It is an arithmetic number, because the mean of its divisors is an integer number (781664715).

Almost surely, 2^21310031000 is an apocalyptic number.

21310031000 is a gapful number since it is divisible by the number (20) 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 21310031000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25013270880).

21310031000 is an abundant number, since it is smaller than the sum of its proper divisors (28716510760).

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

21310031000 is a wasteful number, since it uses less digits than its factorization.

21310031000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68853 (or 68839 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 11.

Adding to 21310031000 its reverse (13001312), we get a palindrome (21323032312).

The spelling of 21310031000 in words is "twenty-one billion, three hundred ten million, thirty-one thousand".