72177920 has 144 divisors (see below), whose sum is σ = 190729728. Its totient is φ = 26050560.

The previous prime is 72177899. The next prime is 72177943. The reversal of 72177920 is 2977127.

72177920 = T₂₅₄ + T₂₅₅ + ... + T₇₆₅.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 674507 + ... + 674613.

It is an arithmetic number, because the mean of its divisors is an integer number (1324512).

Almost surely, 2^72177920 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 72177920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95364864).

72177920 is an abundant number, since it is smaller than the sum of its proper divisors (118551808).

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

72177920 is a wasteful number, since it uses less digits than its factorization.

72177920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176 (or 162 counting only the distinct ones).

The product of its (nonzero) digits is 12348, while the sum is 35.

The square root of 72177920 is about 8495.7589419663. The cubic root of 72177920 is about 416.3591572848.

The spelling of 72177920 in words is "seventy-two million, one hundred seventy-seven thousand, nine hundred twenty".