64128281 has 4 divisors (see below), whose sum is σ = 73289472. Its totient is φ = 54967092.

The previous prime is 64128277. The next prime is 64128283. The reversal of 64128281 is 18282146.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 64128281 - 2² = 64128277 is a prime.

It is a super-2 number, since 2×64128281² = 8224872848029922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64128283) 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, 4580585 + ... + 4580598.

It is an arithmetic number, because the mean of its divisors is an integer number (18322368).

Almost surely, 2^64128281 is an apocalyptic number.

It is an amenable number.

64128281 is a deficient number, since it is larger than the sum of its proper divisors (9161191).

64128281 is an equidigital number, since it uses as much as digits as its factorization.

64128281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9161190.

The product of its digits is 6144, while the sum is 32.

The square root of 64128281 is about 8008.0135489396. The cubic root of 64128281 is about 400.2670737227.

The spelling of 64128281 in words is "sixty-four million, one hundred twenty-eight thousand, two hundred eighty-one".