1561572668 has 12 divisors (see below), whose sum is σ = 2736817440. Its totient is φ = 779624832.

The previous prime is 1561572653. The next prime is 1561572709. The reversal of 1561572668 is 8662751651.

It is a hoax number, since the sum of its digits (47) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 287348 + ... + 292731.

It is an arithmetic number, because the mean of its divisors is an integer number (228068120).

Almost surely, 2^1561572668 is an apocalyptic number.

It is an amenable number.

1561572668 is a deficient number, since it is larger than the sum of its proper divisors (1175244772).

1561572668 is a wasteful number, since it uses less digits than its factorization.

1561572668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 580756 (or 580754 counting only the distinct ones).

The product of its digits is 604800, while the sum is 47.

The square root of 1561572668 is about 39516.7390861139. The cubic root of 1561572668 is about 1160.1676006347.

The spelling of 1561572668 in words is "one billion, five hundred sixty-one million, five hundred seventy-two thousand, six hundred sixty-eight".