661072016 has 40 divisors (see below), whose sum is σ = 1470813600. Its totient is φ = 284670720.

The previous prime is 661071977. The next prime is 661072037. The reversal of 661072016 is 610270166.

It is a self number, because there is not a number n which added to its sum of digits gives 661072016.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 95501 + ... + 102188.

It is an arithmetic number, because the mean of its divisors is an integer number (36770340).

Almost surely, 2^661072016 is an apocalyptic number.

It is an amenable number.

661072016 is an abundant number, since it is smaller than the sum of its proper divisors (809741584).

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

661072016 is a wasteful number, since it uses less digits than its factorization.

661072016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197727 (or 197721 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 661072016 is about 25711.3207750983. The cubic root of 661072016 is about 871.1299081298.

The spelling of 661072016 in words is "six hundred sixty-one million, seventy-two thousand, sixteen".