645312407 has 8 divisors (see below), whose sum is σ = 667474080. Its totient is φ = 623456640.

The previous prime is 645312391. The next prime is 645312431. The reversal of 645312407 is 704213546.

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 645312407 - 2⁴ = 645312391 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 (645312307) 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, 72182 + ... + 80627.

It is an arithmetic number, because the mean of its divisors is an integer number (83434260).

Almost surely, 2^645312407 is an apocalyptic number.

645312407 is a deficient number, since it is larger than the sum of its proper divisors (22161673).

645312407 is a wasteful number, since it uses less digits than its factorization.

645312407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152953.

The product of its (nonzero) digits is 20160, while the sum is 32.

The square root of 645312407 is about 25402.9999606346. Note that the first 4 decimals coincide. The cubic root of 645312407 is about 864.1517325931.

The spelling of 645312407 in words is "six hundred forty-five million, three hundred twelve thousand, four hundred seven".