660325621 has 8 divisors (see below), whose sum is σ = 690773400. Its totient is φ = 630389760.

The previous prime is 660325609. The next prime is 660325651. The reversal of 660325621 is 126523066.

It can be written as a sum of positive squares in 4 ways, for example, as 112063396 + 548262225 = 10586^2 + 23415^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 660325621 - 2⁷ = 660325493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660325651) 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, 125340 + ... + 130501.

It is an arithmetic number, because the mean of its divisors is an integer number (86346675).

Almost surely, 2^660325621 is an apocalyptic number.

It is an amenable number.

660325621 is a deficient number, since it is larger than the sum of its proper divisors (30447779).

660325621 is a wasteful number, since it uses less digits than its factorization.

660325621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255959.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 660325621 is about 25696.8017659786. The cubic root of 660325621 is about 870.8019298083.

Adding to 660325621 its reverse (126523066), we get a palindrome (786848687).

The spelling of 660325621 in words is "six hundred sixty million, three hundred twenty-five thousand, six hundred twenty-one".