51691716 has 24 divisors (see below), whose sum is σ = 134015840. Its totient is φ = 17230536.

The previous prime is 51691711. The next prime is 51691721. The reversal of 51691716 is 61719615.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (51691711) and next prime (51691721).

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

It is not an unprimeable number, because it can be changed into a prime (51691711) 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, 239206 + ... + 239421.

Almost surely, 2^51691716 is an apocalyptic number.

It is an amenable number.

51691716 is an abundant number, since it is smaller than the sum of its proper divisors (82324124).

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

51691716 is a wasteful number, since it uses less digits than its factorization.

51691716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478640 (or 478632 counting only the distinct ones).

The product of its digits is 11340, while the sum is 36.

The square root of 51691716 is about 7189.6951256642. The cubic root of 51691716 is about 372.5120420112.

The spelling of 51691716 in words is "fifty-one million, six hundred ninety-one thousand, seven hundred sixteen".