206561042 has 4 divisors (see below), whose sum is σ = 309841566. Its totient is φ = 103280520.

The previous prime is 206561023. The next prime is 206561053. The reversal of 206561042 is 240165602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 240165602 = 2 ⋅120082801.

It can be written as a sum of positive squares in only one way, i.e., 198838201 + 7722841 = 14101^2 + 2779^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51640259 + ... + 51640262.

Almost surely, 2^206561042 is an apocalyptic number.

206561042 is a deficient number, since it is larger than the sum of its proper divisors (103280524).

206561042 is a wasteful number, since it uses less digits than its factorization.

206561042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103280523.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 206561042 is about 14372.2316290825. The cubic root of 206561042 is about 591.1297342794.

The spelling of 206561042 in words is "two hundred six million, five hundred sixty-one thousand, forty-two".