656891901 has 12 divisors (see below), whose sum is σ = 949457340. Its totient is φ = 437644800.

The previous prime is 656891869. The next prime is 656891923. The reversal of 656891901 is 109198656.

It can be written as a sum of positive squares in 2 ways, for example, as 467856900 + 189035001 = 21630^2 + 13749^2 .

It is not a de Polignac number, because 656891901 - 2⁵ = 656891869 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656891941) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8386 + ... + 37203.

It is an arithmetic number, because the mean of its divisors is an integer number (79121445).

Almost surely, 2^656891901 is an apocalyptic number.

It is an amenable number.

656891901 is a deficient number, since it is larger than the sum of its proper divisors (292565439).

656891901 is a wasteful number, since it uses less digits than its factorization.

656891901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47196 (or 47193 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 45.

The square root of 656891901 is about 25629.9024773798. The cubic root of 656891901 is about 869.2899041272.

The spelling of 656891901 in words is "six hundred fifty-six million, eight hundred ninety-one thousand, nine hundred one".