64069981 has 2 divisors, whose sum is σ = 64069982. Its totient is φ = 64069980.

The previous prime is 64069937. The next prime is 64069987. The reversal of 64069981 is 18996046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63520900 + 549081 = 7970^2 + 741^2 .

It is a cyclic number.

It is not a de Polignac number, because 64069981 - 2⁹ = 64069469 is a prime.

It is a super-2 number, since 2×64069981² = 8209924930680722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64069987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32034990 + 32034991.

It is an arithmetic number, because the mean of its divisors is an integer number (32034991).

Almost surely, 2^64069981 is an apocalyptic number.

It is an amenable number.

64069981 is a deficient number, since it is larger than the sum of its proper divisors (1).

64069981 is an equidigital number, since it uses as much as digits as its factorization.

64069981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 93312, while the sum is 43.

The square root of 64069981 is about 8004.3726175135. The cubic root of 64069981 is about 400.1457406427.

The spelling of 64069981 in words is "sixty-four million, sixty-nine thousand, nine hundred eighty-one".