645606442 has 8 divisors (see below), whose sum is σ = 1042902756. Its totient is φ = 297972192.

The previous prime is 645606427. The next prime is 645606449. The reversal of 645606442 is 244606546.

645606442 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 645210801 + 395641 = 25401^2 + 629^2 .

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

It is not an unprimeable number, because it can be changed into a prime (645606449) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12415483 + ... + 12415534.

Almost surely, 2^645606442 is an apocalyptic number.

645606442 is a deficient number, since it is larger than the sum of its proper divisors (397296314).

645606442 is a wasteful number, since it uses less digits than its factorization.

645606442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24831032.

The product of its (nonzero) digits is 138240, while the sum is 37.

The square root of 645606442 is about 25408.7867085384. The cubic root of 645606442 is about 864.2829621959.

The spelling of 645606442 in words is "six hundred forty-five million, six hundred six thousand, four hundred forty-two".