206115421 has 2 divisors, whose sum is σ = 206115422. Its totient is φ = 206115420.

The previous prime is 206115407. The next prime is 206115431. The reversal of 206115421 is 124511602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 131102500 + 75012921 = 11450^2 + 8661^2 .

It is a cyclic number.

It is not a de Polignac number, because 206115421 - 2¹³ = 206107229 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 206115392 and 206115401.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206115431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103057710 + 103057711.

It is an arithmetic number, because the mean of its divisors is an integer number (103057711).

Almost surely, 2^206115421 is an apocalyptic number.

It is an amenable number.

206115421 is a deficient number, since it is larger than the sum of its proper divisors (1).

206115421 is an equidigital number, since it uses as much as digits as its factorization.

206115421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 206115421 is about 14356.7204124062. The cubic root of 206115421 is about 590.7043402873.

The spelling of 206115421 in words is "two hundred six million, one hundred fifteen thousand, four hundred twenty-one".