661264969 has 2 divisors, whose sum is σ = 661264970. Its totient is φ = 661264968.

The previous prime is 661264957. The next prime is 661264991. The reversal of 661264969 is 969462166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 586269369 + 74995600 = 24213^2 + 8660^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661264969 is a prime.

It is a super-2 number, since 2×661264969² = 874542718453141922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (661264909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330632484 + 330632485.

It is an arithmetic number, because the mean of its divisors is an integer number (330632485).

Almost surely, 2^661264969 is an apocalyptic number.

It is an amenable number.

661264969 is a deficient number, since it is larger than the sum of its proper divisors (1).

661264969 is an equidigital number, since it uses as much as digits as its factorization.

661264969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 839808, while the sum is 49.

The square root of 661264969 is about 25715.0727978748. The cubic root of 661264969 is about 871.2146547101.

The spelling of 661264969 in words is "six hundred sixty-one million, two hundred sixty-four thousand, nine hundred sixty-nine".