51564404021 has 8 divisors (see below), whose sum is σ = 55642188000. Its totient is φ = 47502518832.

The previous prime is 51564404009. The next prime is 51564404069. The reversal of 51564404021 is 12040446515.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51564404021 - 2³⁰ = 50490662197 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 (51564404821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3967955 + ... + 3980928.

It is an arithmetic number, because the mean of its divisors is an integer number (6955273500).

Almost surely, 2^51564404021 is an apocalyptic number.

It is an amenable number.

51564404021 is a deficient number, since it is larger than the sum of its proper divisors (4077783979).

51564404021 is a wasteful number, since it uses less digits than its factorization.

51564404021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7949395.

The product of its (nonzero) digits is 19200, while the sum is 32.

The spelling of 51564404021 in words is "fifty-one billion, five hundred sixty-four million, four hundred four thousand, twenty-one".