68291257 has 4 divisors (see below), whose sum is σ = 68309136. Its totient is φ = 68273380.

The previous prime is 68291243. The next prime is 68291287. The reversal of 68291257 is 75219286.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 68291257 - 2⁷ = 68291129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68291207) 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, 643 + ... + 11704.

It is an arithmetic number, because the mean of its divisors is an integer number (17077284).

Almost surely, 2^68291257 is an apocalyptic number.

It is an amenable number.

68291257 is a deficient number, since it is larger than the sum of its proper divisors (17879).

68291257 is a wasteful number, since it uses less digits than its factorization.

68291257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17878.

The product of its digits is 60480, while the sum is 40.

The square root of 68291257 is about 8263.8524309186. The cubic root of 68291257 is about 408.7474304595.

The spelling of 68291257 in words is "sixty-eight million, two hundred ninety-one thousand, two hundred fifty-seven".