68631491 has 2 divisors, whose sum is σ = 68631492. Its totient is φ = 68631490.

The previous prime is 68631481. The next prime is 68631503. The reversal of 68631491 is 19413686.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 68631491 - 2²² = 64437187 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (68631481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34315745 + 34315746.

It is an arithmetic number, because the mean of its divisors is an integer number (34315746).

Almost surely, 2^68631491 is an apocalyptic number.

68631491 is a deficient number, since it is larger than the sum of its proper divisors (1).

68631491 is an equidigital number, since it uses as much as digits as its factorization.

68631491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 38.

The square root of 68631491 is about 8284.4125319784. The cubic root of 68631491 is about 409.4251133881.

The spelling of 68631491 in words is "sixty-eight million, six hundred thirty-one thousand, four hundred ninety-one".