72921770 has 8 divisors (see below), whose sum is σ = 131259204. Its totient is φ = 29168704.

The previous prime is 72921767. The next prime is 72921781. The reversal of 72921770 is 7712927.

It can be written as a sum of positive squares in 2 ways, for example, as 64272289 + 8649481 = 8017^2 + 2941^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 72921770.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3646079 + ... + 3646098.

Almost surely, 2^72921770 is an apocalyptic number.

72921770 is a deficient number, since it is larger than the sum of its proper divisors (58337434).

72921770 is a wasteful number, since it uses less digits than its factorization.

72921770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7292184.

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

The square root of 72921770 is about 8539.4244536737. The cubic root of 72921770 is about 417.7845741741.

The spelling of 72921770 in words is "seventy-two million, nine hundred twenty-one thousand, seven hundred seventy".