68901991 has 8 divisors (see below), whose sum is σ = 69464304. Its totient is φ = 68342400.

The previous prime is 68901971. The next prime is 68902007. The reversal of 68901991 is 19910986.

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 68901991 - 2²¹ = 66804839 is a prime.

It is a super-3 number, since 3×68901991³ (a number of 24 digits) contains 333 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 (68901971) 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, 97941 + ... + 98641.

It is an arithmetic number, because the mean of its divisors is an integer number (8683038).

Almost surely, 2^68901991 is an apocalyptic number.

68901991 is a deficient number, since it is larger than the sum of its proper divisors (562313).

68901991 is a wasteful number, since it uses less digits than its factorization.

68901991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1361.

The product of its (nonzero) digits is 34992, while the sum is 43.

The square root of 68901991 is about 8300.7223179673. The cubic root of 68901991 is about 409.9623027010.

The spelling of 68901991 in words is "sixty-eight million, nine hundred one thousand, nine hundred ninety-one".