64891263 has 4 divisors (see below), whose sum is σ = 86521688. Its totient is φ = 43260840.

The previous prime is 64891249. The next prime is 64891271. The reversal of 64891263 is 36219846.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 64891263 - 2¹⁰ = 64890239 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64891223) 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, 10815208 + ... + 10815213.

It is an arithmetic number, because the mean of its divisors is an integer number (21630422).

Almost surely, 2^64891263 is an apocalyptic number.

64891263 is a deficient number, since it is larger than the sum of its proper divisors (21630425).

64891263 is a wasteful number, since it uses less digits than its factorization.

64891263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21630424.

The product of its digits is 62208, while the sum is 39.

The square root of 64891263 is about 8055.5113431737. The cubic root of 64891263 is about 401.8482447417.

The spelling of 64891263 in words is "sixty-four million, eight hundred ninety-one thousand, two hundred sixty-three".