64297781 has 2 divisors, whose sum is σ = 64297782. Its totient is φ = 64297780.

The previous prime is 64297777. The next prime is 64297789. The reversal of 64297781 is 18779246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57896881 + 6400900 = 7609^2 + 2530^2 .

It is a cyclic number.

It is not a de Polignac number, because 64297781 - 2² = 64297777 is a prime.

It is a super-2 number, since 2×64297781² = 8268409283047922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64297789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32148890 + 32148891.

It is an arithmetic number, because the mean of its divisors is an integer number (32148891).

Almost surely, 2^64297781 is an apocalyptic number.

It is an amenable number.

64297781 is a deficient number, since it is larger than the sum of its proper divisors (1).

64297781 is an equidigital number, since it uses as much as digits as its factorization.

64297781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 169344, while the sum is 44.

The square root of 64297781 is about 8018.5897139085. The cubic root of 64297781 is about 400.6194173934.

The spelling of 64297781 in words is "sixty-four million, two hundred ninety-seven thousand, seven hundred eighty-one".