72578261 has 6 divisors (see below), whose sum is σ = 84427830. Its totient is φ = 62209896.

The previous prime is 72578243. The next prime is 72578263. The reversal of 72578261 is 16287527.

It can be written as a sum of positive squares in only one way, i.e., 72573361 + 4900 = 8519^2 + 70^2 .

It is not a de Polignac number, because 72578261 - 2⁶ = 72578197 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 (72578263) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 740546 + ... + 740643.

It is an arithmetic number, because the mean of its divisors is an integer number (14071305).

Almost surely, 2^72578261 is an apocalyptic number.

It is an amenable number.

72578261 is a deficient number, since it is larger than the sum of its proper divisors (11849569).

72578261 is a wasteful number, since it uses less digits than its factorization.

72578261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1481203 (or 1481196 counting only the distinct ones).

The product of its digits is 47040, while the sum is 38.

The square root of 72578261 is about 8519.2875875862. The cubic root of 72578261 is about 417.1275289641.

The spelling of 72578261 in words is "seventy-two million, five hundred seventy-eight thousand, two hundred sixty-one".