21031223130 has 40 divisors (see below), whose sum is σ = 56550624372. Its totient is φ = 5608325952.

The previous prime is 21031223111. The next prime is 21031223153. The reversal of 21031223130 is 3132213012.

It can be written as a sum of positive squares in 2 ways, for example, as 19563337161 + 1467885969 = 139869^2 + 38313^2 .

It is a super-3 number, since 3×21031223130³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 12981427 + ... + 12983046.

Almost surely, 2^21031223130 is an apocalyptic number.

21031223130 is an abundant number, since it is smaller than the sum of its proper divisors (35519401242).

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

21031223130 is a wasteful number, since it uses less digits than its factorization.

21031223130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25964492 (or 25964483 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21031223130 its reverse (3132213012), we get a palindrome (24163436142).

The spelling of 21031223130 in words is "twenty-one billion, thirty-one million, two hundred twenty-three thousand, one hundred thirty".