645336637 has 8 divisors (see below), whose sum is σ = 704255040. Its totient is φ = 586460160.

The previous prime is 645336619. The next prime is 645336667. The reversal of 645336637 is 736633546.

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

It is not a de Polignac number, because 645336637 - 2¹⁹ = 644812349 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645336593 and 645336602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645336667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27808 + ... + 45430.

It is an arithmetic number, because the mean of its divisors is an integer number (88031880).

Almost surely, 2^645336637 is an apocalyptic number.

It is an amenable number.

645336637 is a deficient number, since it is larger than the sum of its proper divisors (58918403).

645336637 is a wasteful number, since it uses less digits than its factorization.

645336637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20963.

The product of its digits is 816480, while the sum is 43.

The square root of 645336637 is about 25403.4768683344. The cubic root of 645336637 is about 864.1625480959.

The spelling of 645336637 in words is "six hundred forty-five million, three hundred thirty-six thousand, six hundred thirty-seven".