661651156166 has 64 divisors (see below), whose sum is σ = 1332703411200. Its totient is φ = 237930168960.

The previous prime is 661651156151. The next prime is 661651156181.

661651156166 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (661651156151) and next prime (661651156181).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 33157160 + ... + 33177108.

It is an arithmetic number, because the mean of its divisors is an integer number (20823490800).

Almost surely, 2^661651156166 is an apocalyptic number.

661651156166 is an abundant number, since it is smaller than the sum of its proper divisors (671052255034).

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

661651156166 is a wasteful number, since it uses less digits than its factorization.

661651156166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36549.

The product of its digits is 1166400, while the sum is 50.

The spelling of 661651156166 in words is "six hundred sixty-one billion, six hundred fifty-one million, one hundred fifty-six thousand, one hundred sixty-six".