72366661 has 4 divisors (see below), whose sum is σ = 72394092. Its totient is φ = 72339232.

The previous prime is 72366659. The next prime is 72366673. The reversal of 72366661 is 16666327.

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

It can be written as a sum of positive squares in 2 ways, for example, as 35034561 + 37332100 = 5919^2 + 6110^2 .

It is a cyclic number.

It is not a de Polignac number, because 72366661 - 2¹ = 72366659 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72366661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72366761) 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, 9280 + ... + 15193.

It is an arithmetic number, because the mean of its divisors is an integer number (18098523).

Almost surely, 2^72366661 is an apocalyptic number.

It is an amenable number.

72366661 is a deficient number, since it is larger than the sum of its proper divisors (27431).

72366661 is a wasteful number, since it uses less digits than its factorization.

72366661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27430.

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

The square root of 72366661 is about 8506.8596438404. The cubic root of 72366661 is about 416.7217596129.

The spelling of 72366661 in words is "seventy-two million, three hundred sixty-six thousand, six hundred sixty-one".