72920 has 16 divisors (see below), whose sum is σ = 164160. Its totient is φ = 29152.

The previous prime is 72911. The next prime is 72923. The reversal of 72920 is 2927.

72920 = T₁₃₁ + T₁₃₂ + ... + T₁₃₈.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 72892 and 72901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72923) by changing a digit.

72920 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 3 ways as a sum of consecutive naturals, for example, 872 + ... + 951.

It is an arithmetic number, because the mean of its divisors is an integer number (10260).

2⁷²⁹²⁰ is an apocalyptic number.

It is an amenable number.

72920 is an abundant number, since it is smaller than the sum of its proper divisors (91240).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82080).

72920 is a wasteful number, since it uses less digits than its factorization.

72920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1834 (or 1830 counting only the distinct ones).

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

The square root of 72920 is about 270.0370344971. The cubic root of 72920 is about 41.7781193909.

Subtracting from 72920 its sum of digits (20), we obtain a square (72900 = 270²).

The spelling of 72920 in words is "seventy-two thousand, nine hundred twenty".