661512960 has 144 divisors (see below), whose sum is σ = 2347574880. Its totient is φ = 176394240.

The previous prime is 661512941. The next prime is 661512967. The reversal of 661512960 is 69215166.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (661512967) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24990 + ... + 44130.

Almost surely, 2^661512960 is an apocalyptic number.

661512960 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661512960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1173787440).

661512960 is an abundant number, since it is smaller than the sum of its proper divisors (1686061920).

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

661512960 is a wasteful number, since it uses less digits than its factorization.

661512960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19171 (or 19151 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 661512960 is about 25719.8942455058. The cubic root of 661512960 is about 871.3235502365.

The spelling of 661512960 in words is "six hundred sixty-one million, five hundred twelve thousand, nine hundred sixty".