561666151566 has 32 divisors (see below), whose sum is σ = 1344158313120. Its totient is φ = 172820354112.

The previous prime is 561666151523. The next prime is 561666151591. The reversal of 561666151566 is 665151666165.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 400046415 + ... + 400047818.

It is an arithmetic number, because the mean of its divisors is an integer number (42004947285).

Almost surely, 2^561666151566 is an apocalyptic number.

561666151566 is an abundant number, since it is smaller than the sum of its proper divisors (782492161554).

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

561666151566 is a wasteful number, since it uses less digits than its factorization.

561666151566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 800094257 (or 800094251 counting only the distinct ones).

The product of its digits is 5832000, while the sum is 54.

The spelling of 561666151566 in words is "five hundred sixty-one billion, six hundred sixty-six million, one hundred fifty-one thousand, five hundred sixty-six".