172997856 has 120 divisors (see below), whose sum is σ = 525438144. Its totient is φ = 55779840.

The previous prime is 172997849. The next prime is 172997861. The reversal of 172997856 is 658799271.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 79276 + ... + 81428.

Almost surely, 2^172997856 is an apocalyptic number.

172997856 is a gapful number since it is divisible by the number (16) 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 172997856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (262719072).

172997856 is an abundant number, since it is smaller than the sum of its proper divisors (352440288).

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

172997856 is a wasteful number, since it uses less digits than its factorization.

172997856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2206 (or 2189 counting only the distinct ones).

The product of its digits is 1905120, while the sum is 54.

The square root of 172997856 is about 13152.8649350626. The cubic root of 172997856 is about 557.2031637172.

The spelling of 172997856 in words is "one hundred seventy-two million, nine hundred ninety-seven thousand, eight hundred fifty-six".