64191965 has 16 divisors (see below), whose sum is σ = 81012096. Its totient is φ = 48734400.

The previous prime is 64191943. The next prime is 64191971. The reversal of 64191965 is 56919146.

It is not a de Polignac number, because 64191965 - 2⁶ = 64191901 is a prime.

It is a super-2 number, since 2×64191965² = 8241216741122450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12935 + ... + 17195.

It is an arithmetic number, because the mean of its divisors is an integer number (5063256).

Almost surely, 2^64191965 is an apocalyptic number.

It is an amenable number.

64191965 is a deficient number, since it is larger than the sum of its proper divisors (16820131).

64191965 is a wasteful number, since it uses less digits than its factorization.

64191965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4420.

The product of its digits is 58320, while the sum is 41.

The square root of 64191965 is about 8011.9888292483. The cubic root of 64191965 is about 400.3995278941.

It can be divided in two parts, 64191 and 965, that added together give a palindrome (65156).

The spelling of 64191965 in words is "sixty-four million, one hundred ninety-one thousand, nine hundred sixty-five".