206120381 has 4 divisors (see below), whose sum is σ = 207020700. Its totient is φ = 205220064.

The previous prime is 206120363. The next prime is 206120399. The reversal of 206120381 is 183021602.

206120381 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 183021602 = 2 ⋅91510801.

It is an interprime number because it is at equal distance from previous prime (206120363) and next prime (206120399).

It can be written as a sum of positive squares in 2 ways, for example, as 170824900 + 35295481 = 13070^2 + 5941^2 .

It is a cyclic number.

It is not a de Polignac number, because 206120381 - 2²² = 201926077 is a prime.

It is a super-2 number, since 2×206120381² = 84971222927170322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206110381) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 449816 + ... + 450273.

It is an arithmetic number, because the mean of its divisors is an integer number (51755175).

Almost surely, 2^206120381 is an apocalyptic number.

It is an amenable number.

206120381 is a deficient number, since it is larger than the sum of its proper divisors (900319).

206120381 is an equidigital number, since it uses as much as digits as its factorization.

206120381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 900318.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 206120381 is about 14356.8931527681. The cubic root of 206120381 is about 590.7090785225.

Adding to 206120381 its reverse (183021602), we get a palindrome (389141983).

The spelling of 206120381 in words is "two hundred six million, one hundred twenty thousand, three hundred eighty-one".