661287966 has 8 divisors (see below), whose sum is σ = 1322575944. Its totient is φ = 220429320.

The previous prime is 661287931. The next prime is 661287971. The reversal of 661287966 is 669782166.

It is a sphenic number, since it is the product of 3 distinct primes.

661287966 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55107325 + ... + 55107336.

It is an arithmetic number, because the mean of its divisors is an integer number (165321993).

Almost surely, 2^661287966 is an apocalyptic number.

661287966 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

661287966 is a wasteful number, since it uses less digits than its factorization.

661287966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110214666.

The product of its digits is 1306368, while the sum is 51.

The square root of 661287966 is about 25715.5199441893. The cubic root of 661287966 is about 871.2247540864.

The spelling of 661287966 in words is "six hundred sixty-one million, two hundred eighty-seven thousand, nine hundred sixty-six".