64953781 has 2 divisors, whose sum is σ = 64953782. Its totient is φ = 64953780.

The previous prime is 64953751. The next prime is 64953793. The reversal of 64953781 is 18735946.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64883025 + 70756 = 8055^2 + 266^2 .

It is a cyclic number.

It is not a de Polignac number, because 64953781 - 2⁷ = 64953653 is a prime.

It is a super-2 number, since 2×64953781² = 8437987332391922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64953731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32476890 + 32476891.

It is an arithmetic number, because the mean of its divisors is an integer number (32476891).

Almost surely, 2^64953781 is an apocalyptic number.

It is an amenable number.

64953781 is a deficient number, since it is larger than the sum of its proper divisors (1).

64953781 is an equidigital number, since it uses as much as digits as its factorization.

64953781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 181440, while the sum is 43.

The square root of 64953781 is about 8059.3908578751. The cubic root of 64953781 is about 401.9772538139.

The spelling of 64953781 in words is "sixty-four million, nine hundred fifty-three thousand, seven hundred eighty-one".