72746221 has 4 divisors (see below), whose sum is σ = 73938844. Its totient is φ = 71553600.

The previous prime is 72746203. The next prime is 72746227. The reversal of 72746221 is 12264727.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12264727 = 23 ⋅533249.

It can be written as a sum of positive squares in 2 ways, for example, as 19236996 + 53509225 = 4386^2 + 7315^2 .

It is a cyclic number.

It is not a de Polignac number, because 72746221 - 2⁵ = 72746189 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 (72746227) 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, 596220 + ... + 596341.

It is an arithmetic number, because the mean of its divisors is an integer number (18484711).

Almost surely, 2^72746221 is an apocalyptic number.

It is an amenable number.

72746221 is a deficient number, since it is larger than the sum of its proper divisors (1192623).

72746221 is a wasteful number, since it uses less digits than its factorization.

72746221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1192622.

The product of its digits is 9408, while the sum is 31.

The square root of 72746221 is about 8529.1395228358. The cubic root of 72746221 is about 417.4490520736.

The spelling of 72746221 in words is "seventy-two million, seven hundred forty-six thousand, two hundred twenty-one".