51501997 has 2 divisors, whose sum is σ = 51501998. Its totient is φ = 51501996.

The previous prime is 51501973. The next prime is 51502007. The reversal of 51501997 is 79910515.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51466276 + 35721 = 7174^2 + 189^2 .

It is a cyclic number.

It is not a de Polignac number, because 51501997 - 2⁷ = 51501869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51501097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25750998 + 25750999.

It is an arithmetic number, because the mean of its divisors is an integer number (25750999).

Almost surely, 2^51501997 is an apocalyptic number.

It is an amenable number.

51501997 is a deficient number, since it is larger than the sum of its proper divisors (1).

51501997 is an equidigital number, since it uses as much as digits as its factorization.

51501997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14175, while the sum is 37.

The square root of 51501997 is about 7176.4891834378. The cubic root of 51501997 is about 372.0557519438.

The spelling of 51501997 in words is "fifty-one million, five hundred one thousand, nine hundred ninety-seven".