72780639 has 8 divisors (see below), whose sum is σ = 99297792. Its totient is φ = 47391960.

The previous prime is 72780629. The next prime is 72780649. The reversal of 72780639 is 93608727.

It is an interprime number because it is at equal distance from previous prime (72780629) and next prime (72780649).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 72780639 - 2¹⁷ = 72649567 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 72780639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72780629) 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, 281967 + ... + 282224.

It is an arithmetic number, because the mean of its divisors is an integer number (12412224).

Almost surely, 2^72780639 is an apocalyptic number.

72780639 is a deficient number, since it is larger than the sum of its proper divisors (26517153).

72780639 is a wasteful number, since it uses less digits than its factorization.

72780639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 564237.

The product of its (nonzero) digits is 127008, while the sum is 42.

The square root of 72780639 is about 8531.1569555366. The cubic root of 72780639 is about 417.5148767811.

The spelling of 72780639 in words is "seventy-two million, seven hundred eighty thousand, six hundred thirty-nine".