51262695666 has 320 divisors, whose sum is σ = 149513253120. Its totient is φ = 12748285440.

The previous prime is 51262695643. The next prime is 51262695697. The reversal of 51262695666 is 66659626215.

It is a happy number.

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

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 111198676 + ... + 111199136.

It is an arithmetic number, because the mean of its divisors is an integer number (467228916).

Almost surely, 2^51262695666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51262695666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74756626560).

51262695666 is an abundant number, since it is smaller than the sum of its proper divisors (98250557454).

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

51262695666 is a wasteful number, since it uses less digits than its factorization.

51262695666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 911 (or 902 counting only the distinct ones).

The product of its digits is 6998400, while the sum is 54.

The spelling of 51262695666 in words is "fifty-one billion, two hundred sixty-two million, six hundred ninety-five thousand, six hundred sixty-six".