51957691 has 2 divisors, whose sum is σ = 51957692. Its totient is φ = 51957690.

The previous prime is 51957623. The next prime is 51957707. The reversal of 51957691 is 19675915.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 51957691 - 2⁹ = 51957179 is a prime.

It is not a weakly prime, because it can be changed into another prime (51957611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25978845 + 25978846.

It is an arithmetic number, because the mean of its divisors is an integer number (25978846).

Almost surely, 2^51957691 is an apocalyptic number.

51957691 is a deficient number, since it is larger than the sum of its proper divisors (1).

51957691 is an equidigital number, since it uses as much as digits as its factorization.

51957691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 85050, while the sum is 43.

The square root of 51957691 is about 7208.1683526399. The cubic root of 51957691 is about 373.1498582052.

The spelling of 51957691 in words is "fifty-one million, nine hundred fifty-seven thousand, six hundred ninety-one".