121557187 has 2 divisors, whose sum is σ = 121557188. Its totient is φ = 121557186.

The previous prime is 121557133. The next prime is 121557209. The reversal of 121557187 is 781755121.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 121557187 - 2¹¹ = 121555139 is a prime.

It is a super-2 number, since 2×121557187² = 29552299422705938, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (121557487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60778593 + 60778594.

It is an arithmetic number, because the mean of its divisors is an integer number (60778594).

Almost surely, 2^121557187 is an apocalyptic number.

121557187 is a deficient number, since it is larger than the sum of its proper divisors (1).

121557187 is an equidigital number, since it uses as much as digits as its factorization.

121557187 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19600, while the sum is 37.

The square root of 121557187 is about 11025.2975923555. The cubic root of 121557187 is about 495.3667818593.

The spelling of 121557187 in words is "one hundred twenty-one million, five hundred fifty-seven thousand, one hundred eighty-seven".