20172992 has 56 divisors (see below), whose sum is σ = 47024544. Its totient is φ = 8404992.

The previous prime is 20172989. The next prime is 20173051. The reversal of 20172992 is 29927102.

It is a tau number, because it is divible by the number of its divisors (56).

It is a Harshad number since it is a multiple of its sum of digits (32).

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, 15968 + ... + 17184.

It is an arithmetic number, because the mean of its divisors is an integer number (839724).

Almost surely, 2^20172992 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20172992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23512272).

20172992 is an abundant number, since it is smaller than the sum of its proper divisors (26851552).

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

20172992 is a wasteful number, since it uses less digits than its factorization.

20172992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1273 (or 1263 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 20172992 is about 4491.4354053020. The cubic root of 20172992 is about 272.2221368750. Note that the first 3 decimals are identical.

The spelling of 20172992 in words is "twenty million, one hundred seventy-two thousand, nine hundred ninety-two".