20819172 has 24 divisors (see below), whose sum is σ = 52994592. Its totient is φ = 6308800.

The previous prime is 20819143. The next prime is 20819173. The reversal of 20819172 is 27191802.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (20819173) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78729 + ... + 78992.

It is an arithmetic number, because the mean of its divisors is an integer number (2208108).

Almost surely, 2^20819172 is an apocalyptic number.

20819172 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

20819172 is an abundant number, since it is smaller than the sum of its proper divisors (32175420).

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

20819172 is a wasteful number, since it uses less digits than its factorization.

20819172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157739 (or 157737 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 20819172 is about 4562.8030858235. The cubic root of 20819172 is about 275.0982436862.

The spelling of 20819172 in words is "twenty million, eight hundred nineteen thousand, one hundred seventy-two".