661105008 has 240 divisors, whose sum is σ = 2050154496. Its totient is φ = 198190080.

The previous prime is 661104973. The next prime is 661105079. The reversal of 661105008 is 800501166.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4825516 + ... + 4825652.

Almost surely, 2^661105008 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 661105008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1025077248).

661105008 is an abundant number, since it is smaller than the sum of its proper divisors (1389049488).

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

661105008 is a wasteful number, since it uses less digits than its factorization.

661105008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252 (or 243 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 661105008 is about 25711.9623521815. The cubic root of 661105008 is about 871.1443996623.

The spelling of 661105008 in words is "six hundred sixty-one million, one hundred five thousand, eight".