51621555833021 has 4 divisors (see below), whose sum is σ = 51626785460544. Its totient is φ = 51616326205500.

The previous prime is 51621555833017. The next prime is 51621555833027. The reversal of 51621555833021 is 12033855512615.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51621555833021 - 2² = 51621555833017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51621555833027) 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, 2614798955 + ... + 2614818696.

It is an arithmetic number, because the mean of its divisors is an integer number (12906696365136).

Almost surely, 2^{51621555833021} is an apocalyptic number.

It is an amenable number.

51621555833021 is a deficient number, since it is larger than the sum of its proper divisors (5229627523).

51621555833021 is an equidigital number, since it uses as much as digits as its factorization.

51621555833021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5229627522.

The product of its (nonzero) digits is 1080000, while the sum is 47.

The spelling of 51621555833021 in words is "fifty-one trillion, six hundred twenty-one billion, five hundred fifty-five million, eight hundred thirty-three thousand, twenty-one".