561001656 has 16 divisors (see below), whose sum is σ = 1402504200. Its totient is φ = 187000544.

The previous prime is 561001643. The next prime is 561001687. The reversal of 561001656 is 656100165.

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, 11687511 + ... + 11687558.

Almost surely, 2^561001656 is an apocalyptic number.

It is an amenable number.

561001656 is an abundant number, since it is smaller than the sum of its proper divisors (841502544).

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

561001656 is a wasteful number, since it uses less digits than its factorization.

561001656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23375078 (or 23375074 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 561001656 is about 23685.4735228156. The cubic root of 561001656 is about 824.7482089276.

The spelling of 561001656 in words is "five hundred sixty-one million, one thousand, six hundred fifty-six".