645633247 has 8 divisors (see below), whose sum is σ = 738569216. Its totient is φ = 552872952.

The previous prime is 645633221. The next prime is 645633271. The reversal of 645633247 is 742336546.

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

It is a cyclic number.

It is not a de Polignac number, because 645633247 - 2²⁷ = 511415519 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645633277) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35943 + ... + 50824.

It is an arithmetic number, because the mean of its divisors is an integer number (92321152).

Almost surely, 2^645633247 is an apocalyptic number.

645633247 is a deficient number, since it is larger than the sum of its proper divisors (92935969).

645633247 is a wasteful number, since it uses less digits than its factorization.

645633247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87837.

The product of its digits is 362880, while the sum is 40.

The square root of 645633247 is about 25409.3141780726. The cubic root of 645633247 is about 864.2949234479.

The spelling of 645633247 in words is "six hundred forty-five million, six hundred thirty-three thousand, two hundred forty-seven".