661142968 has 8 divisors (see below), whose sum is σ = 1239643080. Its totient is φ = 330571480.

The previous prime is 661142959. The next prime is 661142987. The reversal of 661142968 is 869241166.

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×661142968² = 874220048271698048, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41321428 + ... + 41321443.

It is an arithmetic number, because the mean of its divisors is an integer number (154955385).

Almost surely, 2^661142968 is an apocalyptic number.

It is an amenable number.

661142968 is a deficient number, since it is larger than the sum of its proper divisors (578500112).

661142968 is a wasteful number, since it uses less digits than its factorization.

661142968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82642877 (or 82642873 counting only the distinct ones).

The product of its digits is 124416, while the sum is 43.

The square root of 661142968 is about 25712.7005193931. The cubic root of 661142968 is about 871.1610727617.

The spelling of 661142968 in words is "six hundred sixty-one million, one hundred forty-two thousand, nine hundred sixty-eight".