655971971 has 4 divisors (see below), whose sum is σ = 667090200. Its totient is φ = 644853744.

The previous prime is 655971959. The next prime is 655971973. The reversal of 655971971 is 179179556.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 655971971 - 2⁶ = 655971907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (655971973) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5559026 + ... + 5559143.

It is an arithmetic number, because the mean of its divisors is an integer number (166772550).

Almost surely, 2^655971971 is an apocalyptic number.

655971971 is a deficient number, since it is larger than the sum of its proper divisors (11118229).

655971971 is a wasteful number, since it uses less digits than its factorization.

655971971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11118228.

The product of its digits is 595350, while the sum is 50.

The square root of 655971971 is about 25611.9497695900. The cubic root of 655971971 is about 868.8839218279.

The spelling of 655971971 in words is "six hundred fifty-five million, nine hundred seventy-one thousand, nine hundred seventy-one".