51491057 has 2 divisors, whose sum is σ = 51491058. Its totient is φ = 51491056.

The previous prime is 51491047. The next prime is 51491059. The reversal of 51491057 is 75019415.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29203216 + 22287841 = 5404^2 + 4721^2 .

It is a cyclic number.

It is not a de Polignac number, because 51491057 - 2⁶ = 51490993 is a prime.

Together with 51491059, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51491059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25745528 + 25745529.

It is an arithmetic number, because the mean of its divisors is an integer number (25745529).

Almost surely, 2^51491057 is an apocalyptic number.

It is an amenable number.

51491057 is a deficient number, since it is larger than the sum of its proper divisors (1).

51491057 is an equidigital number, since it uses as much as digits as its factorization.

51491057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6300, while the sum is 32.

The square root of 51491057 is about 7175.7269318167. The cubic root of 51491057 is about 372.0294061812.

The spelling of 51491057 in words is "fifty-one million, four hundred ninety-one thousand, fifty-seven".