656729172 has 144 divisors (see below), whose sum is σ = 1902211584. Its totient is φ = 189216000.

The previous prime is 656729123. The next prime is 656729173. The reversal of 656729172 is 271927656.

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 congruent number.

It is not an unprimeable number, because it can be changed into a prime (656729173) 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 47 ways as a sum of consecutive naturals, for example, 748398 + ... + 749274.

Almost surely, 2^656729172 is an apocalyptic number.

656729172 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 656729172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (951105792).

656729172 is an abundant number, since it is smaller than the sum of its proper divisors (1245482412).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

656729172 is a wasteful number, since it uses less digits than its factorization.

656729172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 990 (or 985 counting only the distinct ones).

The product of its digits is 317520, while the sum is 45.

The square root of 656729172 is about 25626.7276880994. The cubic root of 656729172 is about 869.2181163850.

The spelling of 656729172 in words is "six hundred fifty-six million, seven hundred twenty-nine thousand, one hundred seventy-two".