645442047 has 8 divisors (see below), whose sum is σ = 956210480. Its totient is φ = 430294680.

The previous prime is 645442013. The next prime is 645442051. The reversal of 645442047 is 740244546.

645442047 is a `hidden beast` number, since 645 + 4 + 4 + 2 + 0 + 4 + 7 = 666.

It is not a de Polignac number, because 645442047 - 2¹² = 645437951 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645442547) by changing a digit.

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, 11952604 + ... + 11952657.

It is an arithmetic number, because the mean of its divisors is an integer number (119526310).

Almost surely, 2^645442047 is an apocalyptic number.

645442047 is a deficient number, since it is larger than the sum of its proper divisors (310768433).

645442047 is a wasteful number, since it uses less digits than its factorization.

645442047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23905270 (or 23905264 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 36.

The square root of 645442047 is about 25405.5514996231. The cubic root of 645442047 is about 864.2095966231.

The spelling of 645442047 in words is "six hundred forty-five million, four hundred forty-two thousand, forty-seven".