51631609 has 2 divisors, whose sum is σ = 51631610. Its totient is φ = 51631608.

The previous prime is 51631603. The next prime is 51631627. The reversal of 51631609 is 90613615.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39100009 + 12531600 = 6253^2 + 3540^2 .

It is a cyclic number.

It is not a de Polignac number, because 51631609 - 2⁵ = 51631577 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51631603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25815804 + 25815805.

It is an arithmetic number, because the mean of its divisors is an integer number (25815805).

Almost surely, 2^51631609 is an apocalyptic number.

It is an amenable number.

51631609 is a deficient number, since it is larger than the sum of its proper divisors (1).

51631609 is an equidigital number, since it uses as much as digits as its factorization.

51631609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4860, while the sum is 31.

The square root of 51631609 is about 7185.5138299220. The cubic root of 51631609 is about 372.3676006498.

The spelling of 51631609 in words is "fifty-one million, six hundred thirty-one thousand, six hundred nine".