121236551 has 2 divisors, whose sum is σ = 121236552. Its totient is φ = 121236550.

The previous prime is 121236527. The next prime is 121236569. The reversal of 121236551 is 155632121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 121236551 - 2⁶ = 121236487 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121236551.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121236251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60618275 + 60618276.

It is an arithmetic number, because the mean of its divisors is an integer number (60618276).

Almost surely, 2^121236551 is an apocalyptic number.

121236551 is a deficient number, since it is larger than the sum of its proper divisors (1).

121236551 is an equidigital number, since it uses as much as digits as its factorization.

121236551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1800, while the sum is 26.

The square root of 121236551 is about 11010.7470682057. The cubic root of 121236551 is about 494.9308490961.

Adding to 121236551 its reverse (155632121), we get a palindrome (276868672).

The spelling of 121236551 in words is "one hundred twenty-one million, two hundred thirty-six thousand, five hundred fifty-one".