661012608 has 64 divisors (see below), whose sum is σ = 1788998400. Its totient is φ = 216173568.

The previous prime is 661012601. The next prime is 661012613. The reversal of 661012608 is 806210166.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (661012601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4113 + ... + 36591.

It is an arithmetic number, because the mean of its divisors is an integer number (27953100).

Almost surely, 2^661012608 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 661012608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (894499200).

661012608 is an abundant number, since it is smaller than the sum of its proper divisors (1127985792).

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

661012608 is a wasteful number, since it uses less digits than its factorization.

661012608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32549 (or 32537 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 661012608 is about 25710.1654603777. The cubic root of 661012608 is about 871.1038123164.

The spelling of 661012608 in words is "six hundred sixty-one million, twelve thousand, six hundred eight".