51666638562 has 128 divisors (see below), whose sum is σ = 146475141120. Its totient is φ = 13107769920.

The previous prime is 51666638509. The next prime is 51666638563. The reversal of 51666638562 is 26583666615.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 51666638499 and 51666638508.

It is not an unprimeable number, because it can be changed into a prime (51666638563) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 34308 + ... + 323280.

It is an arithmetic number, because the mean of its divisors is an integer number (1144337040).

Almost surely, 2^51666638562 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51666638562, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (73237570560).

51666638562 is an abundant number, since it is smaller than the sum of its proper divisors (94808502558).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51666638562 is a wasteful number, since it uses less digits than its factorization.

51666638562 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289045 (or 289039 counting only the distinct ones).

The product of its digits is 9331200, while the sum is 54.

The spelling of 51666638562 in words is "fifty-one billion, six hundred sixty-six million, six hundred thirty-eight thousand, five hundred sixty-two".