645779049 has 16 divisors (see below), whose sum is σ = 906977280. Its totient is φ = 407581200.

The previous prime is 645779023. The next prime is 645779053. The reversal of 645779049 is 940977546.

It is not a de Polignac number, because 645779049 - 2¹⁵ = 645746281 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 645778992 and 645779010.

It is not an unprimeable number, because it can be changed into a prime (645779089) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 108304 + ... + 114110.

It is an arithmetic number, because the mean of its divisors is an integer number (56686080).

Almost surely, 2^645779049 is an apocalyptic number.

It is an amenable number.

645779049 is a deficient number, since it is larger than the sum of its proper divisors (261198231).

645779049 is a wasteful number, since it uses less digits than its factorization.

645779049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7780.

The product of its (nonzero) digits is 1905120, while the sum is 51.

The square root of 645779049 is about 25412.1830821360. The cubic root of 645779049 is about 864.3599791868.

The spelling of 645779049 in words is "six hundred forty-five million, seven hundred seventy-nine thousand, forty-nine".