661876596 has 84 divisors (see below), whose sum is σ = 1765575364. Its totient is φ = 217008720.

The previous prime is 661876591. The next prime is 661876603. The reversal of 661876596 is 695678166.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 2 ways, for example, as 159668496 + 502208100 = 12636^2 + 22410^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661876591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 10850406 + ... + 10850466.

Almost surely, 2^661876596 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 661876596, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (882787682).

661876596 is an abundant number, since it is smaller than the sum of its proper divisors (1103698768).

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

661876596 is an frugal number, since it uses more digits than its factorization.

661876596 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205 (or 66 counting only the distinct ones).

The product of its digits is 3265920, while the sum is 54.

The square root of 661876596 is about 25726.9624324365. The cubic root of 661876596 is about 871.4831775305.

Multiplying 661876596 by its sum of digits (54), we get a cube (35741336184 = 3294³).

The spelling of 661876596 in words is "six hundred sixty-one million, eight hundred seventy-six thousand, five hundred ninety-six".