645357242 has 16 divisors (see below), whose sum is σ = 1002351240. Its totient is φ = 311260992.

The previous prime is 645357233. The next prime is 645357257. The reversal of 645357242 is 242753546.

It can be written as a sum of positive squares in 4 ways, for example, as 198499921 + 446857321 = 14089^2 + 21139^2 .

It is a junction number, because it is equal to n+sod(n) for n = 645357196 and 645357205.

It is an unprimeable number.

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, 65768 + ... + 74940.

Almost surely, 2^645357242 is an apocalyptic number.

645357242 is a deficient number, since it is larger than the sum of its proper divisors (356993998).

645357242 is a wasteful number, since it uses less digits than its factorization.

645357242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10417.

The product of its digits is 201600, while the sum is 38.

The square root of 645357242 is about 25403.8824198192. The cubic root of 645357242 is about 864.1717453008.

The spelling of 645357242 in words is "six hundred forty-five million, three hundred fifty-seven thousand, two hundred forty-two".