121221969929 has 2 divisors, whose sum is σ = 121221969930. Its totient is φ = 121221969928.

The previous prime is 121221969871. The next prime is 121221969931. The reversal of 121221969929 is 929969122121.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 95003883529 + 26218086400 = 308227^2 + 161920^2 .

It is a cyclic number.

It is not a de Polignac number, because 121221969929 - 2¹⁶ = 121221904393 is a prime.

Together with 121221969931, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (121221969329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60610984964 + 60610984965.

It is an arithmetic number, because the mean of its divisors is an integer number (60610984965).

Almost surely, 2^121221969929 is an apocalyptic number.

It is an amenable number.

121221969929 is a deficient number, since it is larger than the sum of its proper divisors (1).

121221969929 is an equidigital number, since it uses as much as digits as its factorization.

121221969929 is an evil number, because the sum of its binary digits is even.

The product of its digits is 629856, while the sum is 53.

The spelling of 121221969929 in words is "one hundred twenty-one billion, two hundred twenty-one million, nine hundred sixty-nine thousand, nine hundred twenty-nine".