642981206 has 16 divisors (see below), whose sum is σ = 1105332480. Its totient is φ = 274793640.

The previous prime is 642981203. The next prime is 642981221. The reversal of 642981206 is 602189246.

642981206 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 642981206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642981203) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58940 + ... + 68991.

It is an arithmetic number, because the mean of its divisors is an integer number (69083280).

Almost surely, 2^642981206 is an apocalyptic number.

642981206 is a deficient number, since it is larger than the sum of its proper divisors (462351274).

642981206 is a wasteful number, since it uses less digits than its factorization.

642981206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128299.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 642981206 is about 25357.0740819993. The cubic root of 642981206 is about 863.1098898828.

The spelling of 642981206 in words is "six hundred forty-two million, nine hundred eighty-one thousand, two hundred six".