64857491 has 2 divisors, whose sum is σ = 64857492. Its totient is φ = 64857490.

The previous prime is 64857451. The next prime is 64857517. The reversal of 64857491 is 19475846.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 64857491 - 2¹⁴ = 64841107 is a prime.

It is not a weakly prime, because it can be changed into another prime (64857451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32428745 + 32428746.

It is an arithmetic number, because the mean of its divisors is an integer number (32428746).

Almost surely, 2^64857491 is an apocalyptic number.

64857491 is a deficient number, since it is larger than the sum of its proper divisors (1).

64857491 is an equidigital number, since it uses as much as digits as its factorization.

64857491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 44.

The square root of 64857491 is about 8053.4148657573. The cubic root of 64857491 is about 401.7785200294.

The spelling of 64857491 in words is "sixty-four million, eight hundred fifty-seven thousand, four hundred ninety-one".