661160641 has 2 divisors, whose sum is σ = 661160642. Its totient is φ = 661160640.

The previous prime is 661160593. The next prime is 661160657. The reversal of 661160641 is 146061166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 598291600 + 62869041 = 24460^2 + 7929^2 .

It is a cyclic number.

It is not a de Polignac number, because 661160641 - 2²⁹ = 124289729 is a prime.

It is not a weakly prime, because it can be changed into another prime (661160681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330580320 + 330580321.

It is an arithmetic number, because the mean of its divisors is an integer number (330580321).

Almost surely, 2^661160641 is an apocalyptic number.

It is an amenable number.

661160641 is a deficient number, since it is larger than the sum of its proper divisors (1).

661160641 is an equidigital number, since it uses as much as digits as its factorization.

661160641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 661160641 is about 25713.0441799488. The cubic root of 661160641 is about 871.1688350225.

The spelling of 661160641 in words is "six hundred sixty-one million, one hundred sixty thousand, six hundred forty-one".