661615007 has 2 divisors, whose sum is σ = 661615008. Its totient is φ = 661615006.

The previous prime is 661614937. The next prime is 661615013. The reversal of 661615007 is 700516166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661615007 - 2¹⁸ = 661352863 is a prime.

It is a super-2 number, since 2×661615007² = 875468834975220098, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661615307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330807503 + 330807504.

It is an arithmetic number, because the mean of its divisors is an integer number (330807504).

Almost surely, 2^661615007 is an apocalyptic number.

661615007 is a deficient number, since it is larger than the sum of its proper divisors (1).

661615007 is an equidigital number, since it uses as much as digits as its factorization.

661615007 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 661615007 is about 25721.8779835377. The cubic root of 661615007 is about 871.3683522726.

The spelling of 661615007 in words is "six hundred sixty-one million, six hundred fifteen thousand, seven".