64491251 has 8 divisors (see below), whose sum is σ = 74492784. Its totient is φ = 55179520.

The previous prime is 64491239. The next prime is 64491257. The reversal of 64491251 is 15219446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 64491251 - 2¹⁰ = 64490227 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64491257) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 172250 + ... + 172623.

It is an arithmetic number, because the mean of its divisors is an integer number (9311598).

Almost surely, 2^64491251 is an apocalyptic number.

64491251 is a deficient number, since it is larger than the sum of its proper divisors (10001533).

64491251 is a wasteful number, since it uses less digits than its factorization.

64491251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344901.

The product of its digits is 8640, while the sum is 32.

The square root of 64491251 is about 8030.6444946841. The cubic root of 64491251 is about 401.0208321215.

The spelling of 64491251 in words is "sixty-four million, four hundred ninety-one thousand, two hundred fifty-one".