68263991 has 4 divisors (see below), whose sum is σ = 68380872. Its totient is φ = 68147112.

The previous prime is 68263961. The next prime is 68263997. The reversal of 68263991 is 19936286.

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

It is a cyclic number.

It is not a de Polignac number, because 68263991 - 2¹⁰ = 68262967 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 (68263997) 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, 57560 + ... + 58733.

It is an arithmetic number, because the mean of its divisors is an integer number (17095218).

Almost surely, 2^68263991 is an apocalyptic number.

68263991 is a deficient number, since it is larger than the sum of its proper divisors (116881).

68263991 is a wasteful number, since it uses less digits than its factorization.

68263991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116880.

The product of its digits is 139968, while the sum is 44.

The square root of 68263991 is about 8262.2025513782. The cubic root of 68263991 is about 408.6930243198.

The spelling of 68263991 in words is "sixty-eight million, two hundred sixty-three thousand, nine hundred ninety-one".