21002455312 has 20 divisors (see below), whose sum is σ = 40850600796. Its totient is φ = 10460364800.

The previous prime is 21002455301. The next prime is 21002455337. The reversal of 21002455312 is 21355420012.

It can be written as a sum of positive squares in 2 ways, for example, as 20919572496 + 82882816 = 144636^2 + 9104^2 .

It is a super-2 number, since 2×21002455312² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2549689 + ... + 2557912.

Almost surely, 2^21002455312 is an apocalyptic number.

It is an amenable number.

21002455312 is a deficient number, since it is larger than the sum of its proper divisors (19848145484).

21002455312 is a wasteful number, since it uses less digits than its factorization.

21002455312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5107866 (or 5107860 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

Adding to 21002455312 its reverse (21355420012), we get a palindrome (42357875324).

The spelling of 21002455312 in words is "twenty-one billion, two million, four hundred fifty-five thousand, three hundred twelve".