64091989 has 16 divisors (see below), whose sum is σ = 74027520. Its totient is φ = 54961920.

The previous prime is 64091987. The next prime is 64092031. The reversal of 64091989 is 98919046.

It is not a de Polignac number, because 64091989 - 2¹ = 64091987 is a prime.

It is a super-2 number, since 2×64091989² = 8215566107952242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64091987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15624 + ... + 19294.

It is an arithmetic number, because the mean of its divisors is an integer number (4626720).

Almost surely, 2^64091989 is an apocalyptic number.

It is an amenable number.

64091989 is a deficient number, since it is larger than the sum of its proper divisors (9935531).

64091989 is a wasteful number, since it uses less digits than its factorization.

64091989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3780.

The product of its (nonzero) digits is 139968, while the sum is 46.

The square root of 64091989 is about 8005.7472480712. The cubic root of 64091989 is about 400.1915520049.

It can be divided in two parts, 640 and 91989, that added together give a palindrome (92629).

The spelling of 64091989 in words is "sixty-four million, ninety-one thousand, nine hundred eighty-nine".