64131791 has 4 divisors (see below), whose sum is σ = 65623272. Its totient is φ = 62640312.

The previous prime is 64131779. The next prime is 64131799. The reversal of 64131791 is 19713146.

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

It is a cyclic number.

It is not a de Polignac number, because 64131791 - 2¹⁴ = 64115407 is a prime.

It is a super-2 number, since 2×64131791² = 8225773233735362, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64131799) 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, 745676 + ... + 745761.

It is an arithmetic number, because the mean of its divisors is an integer number (16405818).

Almost surely, 2^64131791 is an apocalyptic number.

64131791 is a deficient number, since it is larger than the sum of its proper divisors (1491481).

64131791 is a wasteful number, since it uses less digits than its factorization.

64131791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1491480.

The product of its digits is 4536, while the sum is 32.

The square root of 64131791 is about 8008.2327014142. The cubic root of 64131791 is about 400.2743763344.

The spelling of 64131791 in words is "sixty-four million, one hundred thirty-one thousand, seven hundred ninety-one".