72019666 has 8 divisors (see below), whose sum is σ = 109099404. Its totient is φ = 35653200.

The previous prime is 72019663. The next prime is 72019691. The reversal of 72019666 is 66691027.

It can be written as a sum of positive squares in 2 ways, for example, as 70073641 + 1946025 = 8371^2 + 1395^2 .

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

It is not an unprimeable number, because it can be changed into a prime (72019663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 178065 + ... + 178468.

Almost surely, 2^72019666 is an apocalyptic number.

72019666 is a deficient number, since it is larger than the sum of its proper divisors (37079738).

72019666 is a wasteful number, since it uses less digits than its factorization.

72019666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356636.

The product of its (nonzero) digits is 27216, while the sum is 37.

The square root of 72019666 is about 8486.4401252822. The cubic root of 72019666 is about 416.0546379480.

The spelling of 72019666 in words is "seventy-two million, nineteen thousand, six hundred sixty-six".