206121157 has 8 divisors (see below), whose sum is σ = 225086400. Its totient is φ = 187193760.

The previous prime is 206121151. The next prime is 206121169. The reversal of 206121157 is 751121602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 206121157 - 2⁷ = 206121029 is a prime.

It is a super-3 number, since 3×206121157³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206121151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2608 + ... + 20470.

It is an arithmetic number, because the mean of its divisors is an integer number (28135800).

Almost surely, 2^206121157 is an apocalyptic number.

It is an amenable number.

206121157 is a deficient number, since it is larger than the sum of its proper divisors (18965243).

206121157 is a wasteful number, since it uses less digits than its factorization.

206121157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18923.

The product of its (nonzero) digits is 840, while the sum is 25.

The square root of 206121157 is about 14356.9201780883. The cubic root of 206121157 is about 590.7098198201.

Adding to 206121157 its reverse (751121602), we get a palindrome (957242759).

The spelling of 206121157 in words is "two hundred six million, one hundred twenty-one thousand, one hundred fifty-seven".