51642261579 has 4 divisors (see below), whose sum is σ = 68856348776. Its totient is φ = 34428174384.

The previous prime is 51642261557. The next prime is 51642261607. The reversal of 51642261579 is 97516224615.

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

It is not a de Polignac number, because 51642261579 - 2²⁰ = 51641213003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51642261779) 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, 8607043594 + ... + 8607043599.

It is an arithmetic number, because the mean of its divisors is an integer number (17214087194).

Almost surely, 2^51642261579 is an apocalyptic number.

51642261579 is a deficient number, since it is larger than the sum of its proper divisors (17214087197).

51642261579 is a wasteful number, since it uses less digits than its factorization.

51642261579 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17214087196.

The product of its digits is 907200, while the sum is 48.

The spelling of 51642261579 in words is "fifty-one billion, six hundred forty-two million, two hundred sixty-one thousand, five hundred seventy-nine".