21123131202 has 48 divisors (see below), whose sum is σ = 46905250392. Its totient is φ = 6866058240.

The previous prime is 21123131201. The next prime is 21123131203. The reversal of 21123131202 is 20213132112.

It is an interprime number because it is at equal distance from previous prime (21123131201) and next prime (21123131203).

It can be written as a sum of positive squares in 4 ways, for example, as 21010792401 + 112338801 = 144951^2 + 10599^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21123131201) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1925878 + ... + 1936814.

Almost surely, 2^21123131202 is an apocalyptic number.

21123131202 is an abundant number, since it is smaller than the sum of its proper divisors (25782119190).

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

21123131202 is a wasteful number, since it uses less digits than its factorization.

21123131202 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13603 (or 13600 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21123131202 its reverse (20213132112), we get a palindrome (41336263314).

The spelling of 21123131202 in words is "twenty-one billion, one hundred twenty-three million, one hundred thirty-one thousand, two hundred two".