660465621 has 12 divisors (see below), whose sum is σ = 954538572. Its totient is φ = 440064576.

The previous prime is 660465601. The next prime is 660465649. The reversal of 660465621 is 126564066.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 341843121 + 318622500 = 18489^2 + 17850^2 .

It is not a de Polignac number, because 660465621 - 2⁶ = 660465557 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660465601) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2656 + ... + 36441.

It is an arithmetic number, because the mean of its divisors is an integer number (79544881).

Almost surely, 2^660465621 is an apocalyptic number.

It is an amenable number.

660465621 is a deficient number, since it is larger than the sum of its proper divisors (294072951).

660465621 is a wasteful number, since it uses less digits than its factorization.

660465621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40980 (or 40977 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 660465621 is about 25699.5256960124. The cubic root of 660465621 is about 870.8634669507.

The spelling of 660465621 in words is "six hundred sixty million, four hundred sixty-five thousand, six hundred twenty-one".