64987281 has 12 divisors (see below), whose sum is σ = 96408052. Its totient is φ = 42153696.

The previous prime is 64987193. The next prime is 64987313. The reversal of 64987281 is 18278946.

It can be written as a sum of positive squares in 2 ways, for example, as 61779600 + 3207681 = 7860^2 + 1791^2 .

It is not a de Polignac number, because 64987281 - 2⁹ = 64986769 is a prime.

It is a super-2 number, since 2×64987281² = 8446693383545922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (64987781) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 97246 + ... + 97911.

Almost surely, 2^64987281 is an apocalyptic number.

It is an amenable number.

64987281 is a deficient number, since it is larger than the sum of its proper divisors (31420771).

64987281 is a wasteful number, since it uses less digits than its factorization.

64987281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195200 (or 195197 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 64987281 is about 8061.4689108127. The cubic root of 64987281 is about 402.0463487066.

The spelling of 64987281 in words is "sixty-four million, nine hundred eighty-seven thousand, two hundred eighty-one".