64458991 has 4 divisors (see below), whose sum is σ = 64786392. Its totient is φ = 64131592.

The previous prime is 64458913. The next prime is 64458997. The reversal of 64458991 is 19985446.

It is a happy number.

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 64458991 - 2²¹ = 62361839 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 (64458997) 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 3 ways as a sum of consecutive naturals, for example, 163405 + ... + 163798.

It is an arithmetic number, because the mean of its divisors is an integer number (16196598).

Almost surely, 2^64458991 is an apocalyptic number.

64458991 is a deficient number, since it is larger than the sum of its proper divisors (327401).

64458991 is a wasteful number, since it uses less digits than its factorization.

64458991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327400.

The product of its digits is 311040, while the sum is 46.

The square root of 64458991 is about 8028.6356873382. The cubic root of 64458991 is about 400.9539543691.

It can be divided in two parts, 644589 and 91, that added together give a triangular number (644680 = T₁₁₃₅).

The spelling of 64458991 in words is "sixty-four million, four hundred fifty-eight thousand, nine hundred ninety-one".