655172621 has 8 divisors (see below), whose sum is σ = 672071040. Its totient is φ = 638397568.

The previous prime is 655172603. The next prime is 655172659. The reversal of 655172621 is 126271556.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-655172621 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 (655172681) 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, 20036 + ... + 41373.

It is an arithmetic number, because the mean of its divisors is an integer number (84008880).

Almost surely, 2^655172621 is an apocalyptic number.

It is an amenable number.

655172621 is a deficient number, since it is larger than the sum of its proper divisors (16898419).

655172621 is a wasteful number, since it uses less digits than its factorization.

655172621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61683.

The product of its digits is 25200, while the sum is 35.

The square root of 655172621 is about 25596.3399922723. The cubic root of 655172621 is about 868.5308454254.

The spelling of 655172621 in words is "six hundred fifty-five million, one hundred seventy-two thousand, six hundred twenty-one".