660698891 has 2 divisors, whose sum is σ = 660698892. Its totient is φ = 660698890.

The previous prime is 660698879. The next prime is 660698903. The reversal of 660698891 is 198896066.

It is a balanced prime because it is at equal distance from previous prime (660698879) and next prime (660698903).

It is a cyclic number.

It is not a de Polignac number, because 660698891 - 2¹⁴ = 660682507 is a prime.

It is not a weakly prime, because it can be changed into another prime (660698491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330349445 + 330349446.

It is an arithmetic number, because the mean of its divisors is an integer number (330349446).

Almost surely, 2^660698891 is an apocalyptic number.

660698891 is a deficient number, since it is larger than the sum of its proper divisors (1).

660698891 is an equidigital number, since it uses as much as digits as its factorization.

660698891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1119744, while the sum is 53.

The square root of 660698891 is about 25704.0637059590. The cubic root of 660698891 is about 870.9659817033.

The spelling of 660698891 in words is "six hundred sixty million, six hundred ninety-eight thousand, eight hundred ninety-one".