172123640 has 64 divisors (see below), whose sum is σ = 441624960. Its totient is φ = 59811840.

The previous prime is 172123631. The next prime is 172123643. The reversal of 172123640 is 46321271.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172123643) 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 15 ways as a sum of consecutive naturals, for example, 896 + ... + 18575.

It is an arithmetic number, because the mean of its divisors is an integer number (6900390).

Almost surely, 2^172123640 is an apocalyptic number.

172123640 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 172123640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (220812480).

172123640 is an abundant number, since it is smaller than the sum of its proper divisors (269501320).

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

172123640 is a wasteful number, since it uses less digits than its factorization.

172123640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19512 (or 19508 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 172123640 is about 13119.5899326160. The cubic root of 172123640 is about 556.2630003274.

The spelling of 172123640 in words is "one hundred seventy-two million, one hundred twenty-three thousand, six hundred forty".