172861920 has 288 divisors, whose sum is σ = 735920640. Its totient is φ = 35896320.

The previous prime is 172861919. The next prime is 172861937. The reversal of 172861920 is 29168271.

172861920 is a `hidden beast` number, since 17 + 2 + 8 + 619 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

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, 110101 + ... + 111659.

It is an arithmetic number, because the mean of its divisors is an integer number (2555280).

Almost surely, 2^172861920 is an apocalyptic number.

172861920 is a gapful number since it is divisible by the number (10) 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 172861920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (367960320).

172861920 is an abundant number, since it is smaller than the sum of its proper divisors (563058720).

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

172861920 is a wasteful number, since it uses less digits than its factorization.

172861920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1598 (or 1587 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 172861920 is about 13147.6963761718. The cubic root of 172861920 is about 557.0571815285.

The spelling of 172861920 in words is "one hundred seventy-two million, eight hundred sixty-one thousand, nine hundred twenty".