206919961 has 2 divisors, whose sum is σ = 206919962. Its totient is φ = 206919960.

The previous prime is 206919943. The next prime is 206919997. The reversal of 206919961 is 169919602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 155151936 + 51768025 = 12456^2 + 7195^2 .

It is a cyclic number.

It is not a de Polignac number, because 206919961 - 2⁵ = 206919929 is a prime.

It is not a weakly prime, because it can be changed into another prime (206919931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103459980 + 103459981.

It is an arithmetic number, because the mean of its divisors is an integer number (103459981).

Almost surely, 2^206919961 is an apocalyptic number.

It is an amenable number.

206919961 is a deficient number, since it is larger than the sum of its proper divisors (1).

206919961 is an equidigital number, since it uses as much as digits as its factorization.

206919961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 52488, while the sum is 43.

The square root of 206919961 is about 14384.7127534755. The cubic root of 206919961 is about 591.4719171074.

The spelling of 206919961 in words is "two hundred six million, nine hundred nineteen thousand, nine hundred sixty-one".