561661954 has 16 divisors (see below), whose sum is σ = 963288000. Its totient is φ = 240602544.

The previous prime is 561661931. The next prime is 561661967. The reversal of 561661954 is 459166165.

It is a self number, because there is not a number n which added to its sum of digits gives 561661954.

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, 27817 + ... + 43555.

It is an arithmetic number, because the mean of its divisors is an integer number (60205500).

Almost surely, 2^561661954 is an apocalyptic number.

561661954 is a deficient number, since it is larger than the sum of its proper divisors (401626046).

561661954 is a wasteful number, since it uses less digits than its factorization.

561661954 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18297.

The product of its digits is 194400, while the sum is 43.

The square root of 561661954 is about 23699.4083048501. The cubic root of 561661954 is about 825.0716578101.

The spelling of 561661954 in words is "five hundred sixty-one million, six hundred sixty-one thousand, nine hundred fifty-four".