21002403412 has 6 divisors (see below), whose sum is σ = 36754205978. Its totient is φ = 10501201704.

The previous prime is 21002403391. The next prime is 21002403413. The reversal of 21002403412 is 21430420012.

It can be written as a sum of positive squares in only one way, i.e., 17319612816 + 3682790596 = 131604^2 + 60686^2 .

It is a super-2 number, since 2×21002403412² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21002403412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002403413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2625300423 + ... + 2625300430.

Almost surely, 2^21002403412 is an apocalyptic number.

It is an amenable number.

21002403412 is a deficient number, since it is larger than the sum of its proper divisors (15751802566).

21002403412 is a wasteful number, since it uses less digits than its factorization.

21002403412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5250600857 (or 5250600855 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

Adding to 21002403412 its reverse (21430420012), we get a palindrome (42432823424).

The spelling of 21002403412 in words is "twenty-one billion, two million, four hundred three thousand, four hundred twelve".