21124200402 has 12 divisors (see below), whose sum is σ = 45769100910. Its totient is φ = 7041400128.

The previous prime is 21124200401. The next prime is 21124200467. The reversal of 21124200402 is 20400242112.

21124200402 is a `hidden beast` number, since 21 + 1 + 242 + 0 + 0 + 402 = 666.

It can be written as a sum of positive squares in only one way, i.e., 19340743041 + 1783457361 = 139071^2 + 42231^2 .

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 1173566689 = 21124200402 / (2 + 1 + 1 + 2 + 4 + 2 + 0 + 0 + 4 + 0 + 2).

It is not an unprimeable number, because it can be changed into a prime (21124200401) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 586783327 + ... + 586783362.

Almost surely, 2^21124200402 is an apocalyptic number.

21124200402 is an abundant number, since it is smaller than the sum of its proper divisors (24644900508).

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

21124200402 is a wasteful number, since it uses less digits than its factorization.

21124200402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1173566697 (or 1173566694 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 21124200402 its reverse (20400242112), we get a palindrome (41524442514).

The spelling of 21124200402 in words is "twenty-one billion, one hundred twenty-four million, two hundred thousand, four hundred two".