72166663 has 4 divisors (see below), whose sum is σ = 75304368. Its totient is φ = 69028960.

The previous prime is 72166657. The next prime is 72166673. The reversal of 72166663 is 36666127.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72166663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72166603) 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, 1568818 + ... + 1568863.

It is an arithmetic number, because the mean of its divisors is an integer number (18826092).

Almost surely, 2^72166663 is an apocalyptic number.

72166663 is a deficient number, since it is larger than the sum of its proper divisors (3137705).

72166663 is a wasteful number, since it uses less digits than its factorization.

72166663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3137704.

The product of its digits is 54432, while the sum is 37.

The square root of 72166663 is about 8495.0964091057. The cubic root of 72166663 is about 416.3375107816.

The spelling of 72166663 in words is "seventy-two million, one hundred sixty-six thousand, six hundred sixty-three".