172181020 has 24 divisors (see below), whose sum is σ = 394451568. Its totient is φ = 62611200.

The previous prime is 172180997. The next prime is 172181027. The reversal of 172181020 is 20181271.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 172180982 and 172181000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172181027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 391101 + ... + 391540.

It is an arithmetic number, because the mean of its divisors is an integer number (16435482).

Almost surely, 2^172181020 is an apocalyptic number.

172181020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

172181020 is an abundant number, since it is smaller than the sum of its proper divisors (222270548).

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

172181020 is a wasteful number, since it uses less digits than its factorization.

172181020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 782661 (or 782659 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 22.

The square root of 172181020 is about 13121.7765565490. The cubic root of 172181020 is about 556.3248063346.

The spelling of 172181020 in words is "one hundred seventy-two million, one hundred eighty-one thousand, twenty".