645219942 has 8 divisors (see below), whose sum is σ = 1290439896. Its totient is φ = 215073312.

The previous prime is 645219937. The next prime is 645219961. The reversal of 645219942 is 249912546.

645219942 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

645219942 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 645219894 and 645219903.

It is a congruent number.

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, 53768323 + ... + 53768334.

It is an arithmetic number, because the mean of its divisors is an integer number (161304987).

Almost surely, 2^645219942 is an apocalyptic number.

645219942 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645219942 is a wasteful number, since it uses less digits than its factorization.

645219942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107536662.

The product of its digits is 155520, while the sum is 42.

The square root of 645219942 is about 25401.1799332236. The cubic root of 645219942 is about 864.1104566644.

The spelling of 645219942 in words is "six hundred forty-five million, two hundred nineteen thousand, nine hundred forty-two".