68639591 has 8 divisors (see below), whose sum is σ = 72775584. Its totient is φ = 64514560.

The previous prime is 68639587. The next prime is 68639621. The reversal of 68639591 is 19593686.

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

It is a cyclic number.

It is not a de Polignac number, because 68639591 - 2² = 68639587 is a prime.

It is a super-2 number, since 2×68639591² = 9422786905294562, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68639891) 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, 12686 + ... + 17268.

It is an arithmetic number, because the mean of its divisors is an integer number (9096948).

Almost surely, 2^68639591 is an apocalyptic number.

68639591 is a deficient number, since it is larger than the sum of its proper divisors (4135993).

68639591 is a wasteful number, since it uses less digits than its factorization.

68639591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5481.

The product of its digits is 349920, while the sum is 47.

The square root of 68639591 is about 8284.9013874638. The cubic root of 68639591 is about 409.4412197600.

The spelling of 68639591 in words is "sixty-eight million, six hundred thirty-nine thousand, five hundred ninety-one".