51490661 has 2 divisors, whose sum is σ = 51490662. Its totient is φ = 51490660.

The previous prime is 51490633. The next prime is 51490667. The reversal of 51490661 is 16609415.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51394561 + 96100 = 7169^2 + 310^2 .

It is a cyclic number.

It is not a de Polignac number, because 51490661 - 2¹⁴ = 51474277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51490667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25745330 + 25745331.

It is an arithmetic number, because the mean of its divisors is an integer number (25745331).

Almost surely, 2^51490661 is an apocalyptic number.

It is an amenable number.

51490661 is a deficient number, since it is larger than the sum of its proper divisors (1).

51490661 is an equidigital number, since it uses as much as digits as its factorization.

51490661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 51490661 is about 7175.6993387404. The cubic root of 51490661 is about 372.0284524621.

The spelling of 51490661 in words is "fifty-one million, four hundred ninety thousand, six hundred sixty-one".