661595610 has 64 divisors (see below), whose sum is σ = 1717309440. Its totient is φ = 162155520.

The previous prime is 661595609. The next prime is 661595617. The reversal of 661595610 is 16595166.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (661595617) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 90471 + ... + 97509.

It is an arithmetic number, because the mean of its divisors is an integer number (26832960).

Almost surely, 2^661595610 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661595610, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (858654720).

661595610 is an abundant number, since it is smaller than the sum of its proper divisors (1055713830).

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

661595610 is a wasteful number, since it uses less digits than its factorization.

661595610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7303.

The product of its (nonzero) digits is 48600, while the sum is 39.

The square root of 661595610 is about 25721.5009282118. The cubic root of 661595610 is about 871.3598366974.

The spelling of 661595610 in words is "six hundred sixty-one million, five hundred ninety-five thousand, six hundred ten".