122688991 has 2 divisors, whose sum is σ = 122688992. Its totient is φ = 122688990.

The previous prime is 122688971. The next prime is 122688997. The reversal of 122688991 is 199886221.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 122688991 - 2¹³ = 122680799 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (122688997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61344495 + 61344496.

It is an arithmetic number, because the mean of its divisors is an integer number (61344496).

Almost surely, 2^122688991 is an apocalyptic number.

122688991 is a deficient number, since it is larger than the sum of its proper divisors (1).

122688991 is an equidigital number, since it uses as much as digits as its factorization.

122688991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 124416, while the sum is 46.

The square root of 122688991 is about 11076.5062632583. The cubic root of 122688991 is about 496.8994678087.

The spelling of 122688991 in words is "one hundred twenty-two million, six hundred eighty-eight thousand, nine hundred ninety-one".