209491812942 has 16 divisors (see below), whose sum is σ = 422827513680. Its totient is φ = 69189956352.

The previous prime is 209491812931. The next prime is 209491812949. The reversal of 209491812942 is 249218194902.

209491812942 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209491812949) 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, 160161283 + ... + 160162590.

It is an arithmetic number, because the mean of its divisors is an integer number (26426719605).

Almost surely, 2^209491812942 is an apocalyptic number.

209491812942 is an abundant number, since it is smaller than the sum of its proper divisors (213335700738).

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

209491812942 is a wasteful number, since it uses less digits than its factorization.

209491812942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320323987.

The product of its (nonzero) digits is 746496, while the sum is 51.

The spelling of 209491812942 in words is "two hundred nine billion, four hundred ninety-one million, eight hundred twelve thousand, nine hundred forty-two".