172021690 has 16 divisors (see below), whose sum is σ = 311496192. Its totient is φ = 68395984.

The previous prime is 172021679. The next prime is 172021723. The reversal of 172021690 is 96120271.

It is a happy number.

172021690 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×172021690² = 59182923660912200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49834 + ... + 53173.

It is an arithmetic number, because the mean of its divisors is an integer number (19468512).

Almost surely, 2^172021690 is an apocalyptic number.

172021690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

172021690 is a deficient number, since it is larger than the sum of its proper divisors (139474502).

172021690 is a wasteful number, since it uses less digits than its factorization.

172021690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103181.

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 172021690 is about 13115.7039460335. The cubic root of 172021690 is about 556.1531525200.

The spelling of 172021690 in words is "one hundred seventy-two million, twenty-one thousand, six hundred ninety".