645791397 has 8 divisors (see below), whose sum is σ = 866540256. Its totient is φ = 427785072.

The previous prime is 645791351. The next prime is 645791407. The reversal of 645791397 is 793197546.

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

It is not a de Polignac number, because 645791397 - 2⁷ = 645791269 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645791347) 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, 685083 + ... + 686024.

It is an arithmetic number, because the mean of its divisors is an integer number (108317532).

Almost surely, 2^645791397 is an apocalyptic number.

It is an amenable number.

645791397 is a deficient number, since it is larger than the sum of its proper divisors (220748859).

645791397 is a wasteful number, since it uses less digits than its factorization.

645791397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1371267.

The product of its digits is 1428840, while the sum is 51.

The square root of 645791397 is about 25412.4260353080. The cubic root of 645791397 is about 864.3654883203.

The spelling of 645791397 in words is "six hundred forty-five million, seven hundred ninety-one thousand, three hundred ninety-seven".