51066622021 has 4 divisors (see below), whose sum is σ = 51151592044. Its totient is φ = 50981652000.

The previous prime is 51066621967. The next prime is 51066622039. The reversal of 51066622021 is 12022666015.

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

It can be written as a sum of positive squares in 2 ways, for example, as 46237900900 + 4828721121 = 215030^2 + 69489^2 .

It is a cyclic number.

It is not a de Polignac number, because 51066622021 - 2⁹ = 51066621509 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 (51066662021) 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 3 ways as a sum of consecutive naturals, for example, 42484110 + ... + 42485311.

It is an arithmetic number, because the mean of its divisors is an integer number (12787898011).

Almost surely, 2^51066622021 is an apocalyptic number.

It is an amenable number.

51066622021 is a deficient number, since it is larger than the sum of its proper divisors (84970023).

51066622021 is an equidigital number, since it uses as much as digits as its factorization.

51066622021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84970022.

The product of its (nonzero) digits is 8640, while the sum is 31.

The spelling of 51066622021 in words is "fifty-one billion, sixty-six million, six hundred twenty-two thousand, twenty-one".