64861958281 has 4 divisors (see below), whose sum is σ = 64862468100. Its totient is φ = 64861448464.

The previous prime is 64861958269. The next prime is 64861958299. The reversal of 64861958281 is 18285916846.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 59253296400 + 5608661881 = 243420^2 + 74891^2 .

It is a cyclic number.

It is not a de Polignac number, because 64861958281 - 2¹⁹ = 64861433993 is a prime.

It is a super-2 number, since 2×64861958281² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64861958201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111255 + ... + 376963.

It is an arithmetic number, because the mean of its divisors is an integer number (16215617025).

Almost surely, 2^64861958281 is an apocalyptic number.

It is an amenable number.

64861958281 is a deficient number, since it is larger than the sum of its proper divisors (509819).

64861958281 is a wasteful number, since it uses less digits than its factorization.

64861958281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 509818.

The product of its digits is 6635520, while the sum is 58.

The spelling of 64861958281 in words is "sixty-four billion, eight hundred sixty-one million, nine hundred fifty-eight thousand, two hundred eighty-one".