121809551225 has 6 divisors (see below), whose sum is σ = 151043843550. Its totient is φ = 97447640960.

The previous prime is 121809551219. The next prime is 121809551231. The reversal of 121809551225 is 522155908121.

It is an interprime number because it is at equal distance from previous prime (121809551219) and next prime (121809551231).

It can be written as a sum of positive squares in 3 ways, for example, as 766791481 + 121042759744 = 27691^2 + 347912^2 .

It is not a de Polignac number, because 121809551225 - 2²⁴ = 121792774009 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2436191000 + ... + 2436191049.

It is an arithmetic number, because the mean of its divisors is an integer number (25173973925).

Almost surely, 2^121809551225 is an apocalyptic number.

It is an amenable number.

121809551225 is a deficient number, since it is larger than the sum of its proper divisors (29234292325).

121809551225 is an equidigital number, since it uses as much as digits as its factorization.

121809551225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4872382059 (or 4872382054 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 41.

The spelling of 121809551225 in words is "one hundred twenty-one billion, eight hundred nine million, five hundred fifty-one thousand, two hundred twenty-five".