647892251 has 4 divisors (see below), whose sum is σ = 648135000. Its totient is φ = 647649504.

The previous prime is 647892247. The next prime is 647892263. The reversal of 647892251 is 152298746.

It is a happy number.

647892251 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 152298746 = 2 ⋅76149373.

It is a cyclic number.

It is not a de Polignac number, because 647892251 - 2² = 647892247 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (647892851) 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, 117326 + ... + 122723.

It is an arithmetic number, because the mean of its divisors is an integer number (162033750).

Almost surely, 2^647892251 is an apocalyptic number.

647892251 is a deficient number, since it is larger than the sum of its proper divisors (242749).

647892251 is a wasteful number, since it uses less digits than its factorization.

647892251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242748.

The product of its digits is 241920, while the sum is 44.

The square root of 647892251 is about 25453.7276444925. The cubic root of 647892251 is about 865.3017762699.

The spelling of 647892251 in words is "six hundred forty-seven million, eight hundred ninety-two thousand, two hundred fifty-one".