661110156 has 108 divisors (see below), whose sum is σ = 1966287960. Its totient is φ = 186721920.

The previous prime is 661110143. The next prime is 661110167. The reversal of 661110156 is 651011166.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 154891 + ... + 159101.

It is an arithmetic number, because the mean of its divisors is an integer number (18206370).

Almost surely, 2^661110156 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661110156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (983143980).

661110156 is an abundant number, since it is smaller than the sum of its proper divisors (1305177804).

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

661110156 is a wasteful number, since it uses less digits than its factorization.

661110156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4324 (or 4312 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 661110156 is about 25712.0624610318. The cubic root of 661110156 is about 871.1466608461.

The spelling of 661110156 in words is "six hundred sixty-one million, one hundred ten thousand, one hundred fifty-six".