72315661 has 8 divisors (see below), whose sum is σ = 79036704. Its totient is φ = 65619120.

The previous prime is 72315641. The next prime is 72315673. The reversal of 72315661 is 16651327.

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

It is a cyclic number.

It is not a de Polignac number, because 72315661 - 2¹¹ = 72313613 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 (72315641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 355 + ... + 12031.

It is an arithmetic number, because the mean of its divisors is an integer number (9879588).

Almost surely, 2^72315661 is an apocalyptic number.

It is an amenable number.

72315661 is a deficient number, since it is larger than the sum of its proper divisors (6721043).

72315661 is a wasteful number, since it uses less digits than its factorization.

72315661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12251.

The product of its digits is 7560, while the sum is 31.

The square root of 72315661 is about 8503.8615346206. The cubic root of 72315661 is about 416.6238424965.

Adding to 72315661 its reverse (16651327), we get a palindrome (88966988).

It can be divided in two parts, 723 and 15661, that added together give a 14-th power (16384 = 2¹⁴).

The spelling of 72315661 in words is "seventy-two million, three hundred fifteen thousand, six hundred sixty-one".