72172020 has 24 divisors (see below), whose sum is σ = 202081824. Its totient is φ = 19245856.

The previous prime is 72172003. The next prime is 72172031. The reversal of 72172020 is 2027127.

It is a congruent number.

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, 601374 + ... + 601493.

It is an arithmetic number, because the mean of its divisors is an integer number (8420076).

Almost surely, 2^72172020 is an apocalyptic number.

It is an amenable number.

72172020 is an abundant number, since it is smaller than the sum of its proper divisors (129909804).

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

72172020 is a wasteful number, since it uses less digits than its factorization.

72172020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1202879 (or 1202877 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 21.

The square root of 72172020 is about 8495.4117027958. The cubic root of 72172020 is about 416.3478122365.

Adding to 72172020 its reverse (2027127), we get a palindrome (74199147).

The spelling of 72172020 in words is "seventy-two million, one hundred seventy-two thousand, twenty".