51661923629 has 4 divisors (see below), whose sum is σ = 52432997184. Its totient is φ = 50890850076.

The previous prime is 51661923623. The next prime is 51661923653. The reversal of 51661923629 is 92632916615.

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 a de Polignac number, because none of the positive numbers 2^k-51661923629 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 (51661923623) 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, 385536677 + ... + 385536810.

It is an arithmetic number, because the mean of its divisors is an integer number (13108249296).

Almost surely, 2^51661923629 is an apocalyptic number.

It is an amenable number.

51661923629 is a deficient number, since it is larger than the sum of its proper divisors (771073555).

51661923629 is an equidigital number, since it uses as much as digits as its factorization.

51661923629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 771073554.

The product of its digits is 1049760, while the sum is 50.

The spelling of 51661923629 in words is "fifty-one billion, six hundred sixty-one million, nine hundred twenty-three thousand, six hundred twenty-nine".