645278142 has 8 divisors (see below), whose sum is σ = 1290556296. Its totient is φ = 215092712.

The previous prime is 645278111. The next prime is 645278173. The reversal of 645278142 is 241872546.

It is an interprime number because it is at equal distance from previous prime (645278111) and next prime (645278173).

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

645278142 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 645278142.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53773173 + ... + 53773184.

It is an arithmetic number, because the mean of its divisors is an integer number (161319537).

Almost surely, 2^645278142 is an apocalyptic number.

645278142 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.

645278142 is a wasteful number, since it uses less digits than its factorization.

645278142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107546362.

The product of its digits is 107520, while the sum is 39.

The square root of 645278142 is about 25402.3255234634. The cubic root of 645278142 is about 864.1364373227.

The spelling of 645278142 in words is "six hundred forty-five million, two hundred seventy-eight thousand, one hundred forty-two".