72172100 has 216 divisors, whose sum is σ = 216111168. Its totient is φ = 20563200.

The previous prime is 72172099. The next prime is 72172117. The reversal of 72172100 is 127127.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 700649 + ... + 700751.

Almost surely, 2^72172100 is an apocalyptic number.

72172100 is a gapful number since it is divisible by the number (70) 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 72172100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108055584).

72172100 is an abundant number, since it is smaller than the sum of its proper divisors (143939068).

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

72172100 is a wasteful number, since it uses less digits than its factorization.

72172100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 196, while the sum is 20.

The square root of 72172100 is about 8495.4164112185. The cubic root of 72172100 is about 416.3479660718.

Adding to 72172100 its reverse (127127), we get a palindrome (72299227).

It can be divided in two parts, 721 and 72100, that multiplied together give a square (51984100 = 7210²).

The spelling of 72172100 in words is "seventy-two million, one hundred seventy-two thousand, one hundred".