656571949 has 4 divisors (see below), whose sum is σ = 716260320. Its totient is φ = 596883580.

The previous prime is 656571947. The next prime is 656571967. The reversal of 656571949 is 949175656.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 656571949 - 2¹ = 656571947 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 656571896 and 656571905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656571941) 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, 29844169 + ... + 29844190.

It is an arithmetic number, because the mean of its divisors is an integer number (179065080).

Almost surely, 2^656571949 is an apocalyptic number.

It is an amenable number.

656571949 is a deficient number, since it is larger than the sum of its proper divisors (59688371).

656571949 is a wasteful number, since it uses less digits than its factorization.

656571949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59688370.

The product of its digits is 2041200, while the sum is 52.

The square root of 656571949 is about 25623.6599454489. The cubic root of 656571949 is about 869.1487463449.

The spelling of 656571949 in words is "six hundred fifty-six million, five hundred seventy-one thousand, nine hundred forty-nine".