661142959 has 2 divisors, whose sum is σ = 661142960. Its totient is φ = 661142958.

The previous prime is 661142953. The next prime is 661142987. The reversal of 661142959 is 959241166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 661142959 - 2⁷ = 661142831 is a prime.

It is a super-2 number, since 2×661142959² = 874220024470551362, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661142953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330571479 + 330571480.

It is an arithmetic number, because the mean of its divisors is an integer number (330571480).

Almost surely, 2^661142959 is an apocalyptic number.

661142959 is a deficient number, since it is larger than the sum of its proper divisors (1).

661142959 is an equidigital number, since it uses as much as digits as its factorization.

661142959 is an evil number, because the sum of its binary digits is even.

The product of its digits is 116640, while the sum is 43.

The square root of 661142959 is about 25712.7003443823. The cubic root of 661142959 is about 871.1610688087.

The spelling of 661142959 in words is "six hundred sixty-one million, one hundred forty-two thousand, nine hundred fifty-nine".