72166861 has 8 divisors (see below), whose sum is σ = 78331904. Its totient is φ = 66089520.

The previous prime is 72166859. The next prime is 72166873. The reversal of 72166861 is 16866127.

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 72166861 - 2¹ = 72166859 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 72166861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72166841) 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, 20205 + ... + 23506.

It is an arithmetic number, because the mean of its divisors is an integer number (9791488).

Almost surely, 2^72166861 is an apocalyptic number.

It is an amenable number.

72166861 is a deficient number, since it is larger than the sum of its proper divisors (6165043).

72166861 is a wasteful number, since it uses less digits than its factorization.

72166861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43851.

The product of its digits is 24192, while the sum is 37.

The square root of 72166861 is about 8495.1080628795. The cubic root of 72166861 is about 416.3378915426.

The spelling of 72166861 in words is "seventy-two million, one hundred sixty-six thousand, eight hundred sixty-one".