209781942 has 16 divisors (see below), whose sum is σ = 437806080. Its totient is φ = 66886952.

The previous prime is 209781937. The next prime is 209781967. The reversal of 209781942 is 249187902.

209781942 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 209781894 and 209781903.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 759942 + ... + 760217.

It is an arithmetic number, because the mean of its divisors is an integer number (27362880).

Almost surely, 2^209781942 is an apocalyptic number.

209781942 is an abundant number, since it is smaller than the sum of its proper divisors (228024138).

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

209781942 is a wasteful number, since it uses less digits than its factorization.

209781942 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1520187.

The product of its (nonzero) digits is 72576, while the sum is 42.

The square root of 209781942 is about 14483.8510762849. The cubic root of 209781942 is about 594.1863907350.

The spelling of 209781942 in words is "two hundred nine million, seven hundred eighty-one thousand, nine hundred forty-two".