642969966 has 8 divisors (see below), whose sum is σ = 1285939944. Its totient is φ = 214323320.

The previous prime is 642969959. The next prime is 642969967. The reversal of 642969966 is 669969246.

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

642969966 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642969967) 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, 53580825 + ... + 53580836.

It is an arithmetic number, because the mean of its divisors is an integer number (160742493).

Almost surely, 2^642969966 is an apocalyptic number.

642969966 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.

642969966 is a wasteful number, since it uses less digits than its factorization.

642969966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107161666.

The product of its digits is 7558272, while the sum is 57.

The square root of 642969966 is about 25356.8524466267. The cubic root of 642969966 is about 863.1048604918.

The spelling of 642969966 in words is "six hundred forty-two million, nine hundred sixty-nine thousand, nine hundred sixty-six".