645877738 has 8 divisors (see below), whose sum is σ = 1056890880. Its totient is φ = 293580780.

The previous prime is 645877711. The next prime is 645877741. The reversal of 645877738 is 837778546.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14679018 + ... + 14679061.

It is an arithmetic number, because the mean of its divisors is an integer number (132111360).

Almost surely, 2^645877738 is an apocalyptic number.

645877738 is a deficient number, since it is larger than the sum of its proper divisors (411013142).

645877738 is a wasteful number, since it uses less digits than its factorization.

645877738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29358092.

The product of its digits is 7902720, while the sum is 55.

The square root of 645877738 is about 25414.1247734405. The cubic root of 645877738 is about 864.4040079079.

The spelling of 645877738 in words is "six hundred forty-five million, eight hundred seventy-seven thousand, seven hundred thirty-eight".