21051566039 has 4 divisors (see below), whose sum is σ = 24058932624. Its totient is φ = 18044199456.

The previous prime is 21051566033. The next prime is 21051566051. The reversal of 21051566039 is 93066515012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21051566039 - 2⁴ = 21051566023 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21051565993 and 21051566011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21051566033) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1503683282 + ... + 1503683295.

It is an arithmetic number, because the mean of its divisors is an integer number (6014733156).

Almost surely, 2^21051566039 is an apocalyptic number.

21051566039 is a deficient number, since it is larger than the sum of its proper divisors (3007366585).

21051566039 is an equidigital number, since it uses as much as digits as its factorization.

21051566039 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3007366584.

The product of its (nonzero) digits is 48600, while the sum is 38.

The spelling of 21051566039 in words is "twenty-one billion, fifty-one million, five hundred sixty-six thousand, thirty-nine".