72988309 has 4 divisors (see below), whose sum is σ = 74961004. Its totient is φ = 71015616.

The previous prime is 72988283. The next prime is 72988319. The reversal of 72988309 is 90388927.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 59629284 + 13359025 = 7722^2 + 3655^2 .

It is a cyclic number.

It is not a de Polignac number, because 72988309 - 2¹⁷ = 72857237 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 (72988319) 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, 986292 + ... + 986365.

It is an arithmetic number, because the mean of its divisors is an integer number (18740251).

Almost surely, 2^72988309 is an apocalyptic number.

It is an amenable number.

72988309 is a deficient number, since it is larger than the sum of its proper divisors (1972695).

72988309 is a wasteful number, since it uses less digits than its factorization.

72988309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1972694.

The product of its (nonzero) digits is 217728, while the sum is 46.

The square root of 72988309 is about 8543.3195538971. The cubic root of 72988309 is about 417.9116076458.

The spelling of 72988309 in words is "seventy-two million, nine hundred eighty-eight thousand, three hundred nine".