64190591 has 4 divisors (see below), whose sum is σ = 64457184. Its totient is φ = 63924000.

The previous prime is 64190587. The next prime is 64190593. The reversal of 64190591 is 19509146.

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 64190591 - 2² = 64190587 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 (64190593) 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, 132935 + ... + 133416.

It is an arithmetic number, because the mean of its divisors is an integer number (16114296).

Almost surely, 2^64190591 is an apocalyptic number.

64190591 is a deficient number, since it is larger than the sum of its proper divisors (266593).

64190591 is a wasteful number, since it uses less digits than its factorization.

64190591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266592.

The product of its (nonzero) digits is 9720, while the sum is 35.

The square root of 64190591 is about 8011.9030822895. The cubic root of 64190591 is about 400.3966710834.

The spelling of 64190591 in words is "sixty-four million, one hundred ninety thousand, five hundred ninety-one".