20972 has 18 divisors (see below), whose sum is σ = 43092. Its totient is φ = 8904.

The previous prime is 20963. The next prime is 20981. The reversal of 20972 is 27902.

It is an interprime number because it is at equal distance from previous prime (20963) and next prime (20981).

It is a nialpdrome in base 15.

It is an unprimeable number.

20972 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 143 + ... + 249.

It is an arithmetic number, because the mean of its divisors is an integer number (2394).

2²⁰⁹⁷² 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 20972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21546).

20972 is an abundant number, since it is smaller than the sum of its proper divisors (22120).

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

20972 is a wasteful number, since it uses less digits than its factorization.

20972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125 (or 116 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 20.

The square root of 20972 is about 144.8171260590. The cubic root of 20972 is about 27.5769744248.

The spelling of 20972 in words is "twenty thousand, nine hundred seventy-two".