64491369 has 4 divisors (see below), whose sum is σ = 85988496. Its totient is φ = 42994244.

The previous prime is 64491367. The next prime is 64491391. The reversal of 64491369 is 96319446.

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 64491369 - 2¹ = 64491367 is a prime.

It is a super-2 number, since 2×64491369² = 8318273350988322, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 64491369.

It is not an unprimeable number, because it can be changed into a prime (64491367) 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, 10748559 + ... + 10748564.

It is an arithmetic number, because the mean of its divisors is an integer number (21497124).

Almost surely, 2^64491369 is an apocalyptic number.

It is an amenable number.

64491369 is a deficient number, since it is larger than the sum of its proper divisors (21497127).

64491369 is a wasteful number, since it uses less digits than its factorization.

64491369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21497126.

The product of its digits is 139968, while the sum is 42.

The square root of 64491369 is about 8030.6518415381. The cubic root of 64491369 is about 401.0210767047.

The spelling of 64491369 in words is "sixty-four million, four hundred ninety-one thousand, three hundred sixty-nine".