561001655 has 8 divisors (see below), whose sum is σ = 673332912. Its totient is φ = 448714048.

The previous prime is 561001643. The next prime is 561001687. The reversal of 561001655 is 556100165.

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

It is a cyclic number.

It is not a de Polignac number, because 561001655 - 2²² = 556807351 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34724 + ... + 48246.

It is an arithmetic number, because the mean of its divisors is an integer number (84166614).

Almost surely, 2^561001655 is an apocalyptic number.

561001655 is a deficient number, since it is larger than the sum of its proper divisors (112331257).

561001655 is a wasteful number, since it uses less digits than its factorization.

561001655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21825.

The product of its (nonzero) digits is 4500, while the sum is 29.

The square root of 561001655 is about 23685.4735017056. The cubic root of 561001655 is about 824.7482084376.

The spelling of 561001655 in words is "five hundred sixty-one million, one thousand, six hundred fifty-five".