68511581 has 8 divisors (see below), whose sum is σ = 74882304. Its totient is φ = 62400960.

The previous prime is 68511529. The next prime is 68511607. The reversal of 68511581 is 18511586.

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 68511581 - 2²² = 64317277 is a prime.

It is a super-2 number, since 2×68511581² = 9387673462239122, 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 (68513581) 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, 64475 + ... + 65528.

It is an arithmetic number, because the mean of its divisors is an integer number (9360288).

Almost surely, 2^68511581 is an apocalyptic number.

It is an amenable number.

68511581 is a deficient number, since it is larger than the sum of its proper divisors (6370723).

68511581 is a wasteful number, since it uses less digits than its factorization.

68511581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130051.

The product of its digits is 9600, while the sum is 35.

The square root of 68511581 is about 8277.1722828512. The cubic root of 68511581 is about 409.1865310495.

The spelling of 68511581 in words is "sixty-eight million, five hundred eleven thousand, five hundred eighty-one".