72639247 has 2 divisors, whose sum is σ = 72639248. Its totient is φ = 72639246.

The previous prime is 72639239. The next prime is 72639253. The reversal of 72639247 is 74293627.

It is a strong prime.

It is an emirp because it is prime and its reverse (74293627) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72639247 - 2³ = 72639239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72639257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36319623 + 36319624.

It is an arithmetic number, because the mean of its divisors is an integer number (36319624).

Almost surely, 2^72639247 is an apocalyptic number.

72639247 is a deficient number, since it is larger than the sum of its proper divisors (1).

72639247 is an equidigital number, since it uses as much as digits as its factorization.

72639247 is an evil number, because the sum of its binary digits is even.

The product of its digits is 127008, while the sum is 40.

The square root of 72639247 is about 8522.8661258992. The cubic root of 72639247 is about 417.2443307777.

The spelling of 72639247 in words is "seventy-two million, six hundred thirty-nine thousand, two hundred forty-seven".