661124291 has 2 divisors, whose sum is σ = 661124292. Its totient is φ = 661124290.

The previous prime is 661124273. The next prime is 661124327. The reversal of 661124291 is 192421166.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661124291 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (661124591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330562145 + 330562146.

It is an arithmetic number, because the mean of its divisors is an integer number (330562146).

Almost surely, 2^661124291 is an apocalyptic number.

661124291 is a deficient number, since it is larger than the sum of its proper divisors (1).

661124291 is an equidigital number, since it uses as much as digits as its factorization.

661124291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 32.

The square root of 661124291 is about 25712.3373305501. The cubic root of 661124291 is about 871.1528693779.

The spelling of 661124291 in words is "six hundred sixty-one million, one hundred twenty-four thousand, two hundred ninety-one".