21045000051 has 6 divisors (see below), whose sum is σ = 30398333420. Its totient is φ = 14030000028.

The previous prime is 21045000029. The next prime is 21045000059. The reversal of 21045000051 is 15000054012.

21045000051 is a `hidden beast` number, since 210 + 450 + 0 + 0 + 0 + 5 + 1 = 666.

It is not a de Polignac number, because 21045000051 - 2⁵ = 21045000019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21044999988 and 21045000033.

It is not an unprimeable number, because it can be changed into a prime (21045000059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1169166661 + ... + 1169166678.

Almost surely, 2^21045000051 is an apocalyptic number.

21045000051 is a deficient number, since it is larger than the sum of its proper divisors (9353333369).

21045000051 is a wasteful number, since it uses less digits than its factorization.

21045000051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2338333345 (or 2338333342 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

Adding to 21045000051 its reverse (15000054012), we get a palindrome (36045054063).

The spelling of 21045000051 in words is "twenty-one billion, forty-five million, fifty-one", and thus it is an aban number and an uban number.