51211216636 has 24 divisors (see below), whose sum is σ = 94908690576. Its totient is φ = 24094997760.

The previous prime is 51211216633. The next prime is 51211216699. The reversal of 51211216636 is 63661211215.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51211216633) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 322891 + ... + 454621.

It is an arithmetic number, because the mean of its divisors is an integer number (3954528774).

Almost surely, 2^51211216636 is an apocalyptic number.

It is an amenable number.

51211216636 is a deficient number, since it is larger than the sum of its proper divisors (43697473940).

51211216636 is a wasteful number, since it uses less digits than its factorization.

51211216636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137469 (or 137467 counting only the distinct ones).

The product of its digits is 12960, while the sum is 34.

The spelling of 51211216636 in words is "fifty-one billion, two hundred eleven million, two hundred sixteen thousand, six hundred thirty-six".