51621171516 has 36 divisors (see below), whose sum is σ = 137354581000. Its totient is φ = 16301422368.

The previous prime is 51621171499. The next prime is 51621171533. The reversal of 51621171516 is 61517112615.

51621171516 is a `hidden beast` number, since 5 + 1 + 62 + 11 + 71 + 516 = 666.

It is an interprime number because it is at equal distance from previous prime (51621171499) and next prime (51621171533).

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37734091 + ... + 37735458.

Almost surely, 2^51621171516 is an apocalyptic number.

It is an amenable number.

51621171516 is an abundant number, since it is smaller than the sum of its proper divisors (85733409484).

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

51621171516 is a wasteful number, since it uses less digits than its factorization.

51621171516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75469578 (or 75469573 counting only the distinct ones).

The product of its digits is 12600, while the sum is 36.

The spelling of 51621171516 in words is "fifty-one billion, six hundred twenty-one million, one hundred seventy-one thousand, five hundred sixteen".