661142928 has 40 divisors (see below), whose sum is σ = 1766851200. Its totient is φ = 212781184.

The previous prime is 661142887. The next prime is 661142929. The reversal of 661142928 is 829241166.

It is not an unprimeable number, because it can be changed into a prime (661142929) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 236088 + ... + 238871.

It is an arithmetic number, because the mean of its divisors is an integer number (44171280).

Almost surely, 2^661142928 is an apocalyptic number.

It is an amenable number.

661142928 is an abundant number, since it is smaller than the sum of its proper divisors (1105708272).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661142928 is a wasteful number, since it uses less digits than its factorization.

661142928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 474999 (or 474993 counting only the distinct ones).

The product of its digits is 41472, while the sum is 39.

The square root of 661142928 is about 25712.6997415674. The cubic root of 661142928 is about 871.1610551929.

The spelling of 661142928 in words is "six hundred sixty-one million, one hundred forty-two thousand, nine hundred twenty-eight".