656609397 has 4 divisors (see below), whose sum is σ = 875479200. Its totient is φ = 437739596.

The previous prime is 656609381. The next prime is 656609413. The reversal of 656609397 is 793906656.

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 an interprime number because it is at equal distance from previous prime (656609381) and next prime (656609413).

It is a cyclic number.

It is not a de Polignac number, because 656609397 - 2⁴ = 656609381 is a prime.

It is a super-2 number, since 2×656609397² = 862271800457407218, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656609347) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 109434897 + ... + 109434902.

It is an arithmetic number, because the mean of its divisors is an integer number (218869800).

Almost surely, 2^656609397 is an apocalyptic number.

It is an amenable number.

656609397 is a deficient number, since it is larger than the sum of its proper divisors (218869803).

656609397 is a wasteful number, since it uses less digits than its factorization.

656609397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218869802.

The product of its (nonzero) digits is 1837080, while the sum is 51.

The square root of 656609397 is about 25624.3906659261. The cubic root of 656609397 is about 869.1652701818.

It can be divided in two parts, 65660 and 9397, that added together give a palindrome (75057).

The spelling of 656609397 in words is "six hundred fifty-six million, six hundred nine thousand, three hundred ninety-seven".