121551016209 has 32 divisors (see below), whose sum is σ = 196140496896. Its totient is φ = 65363784960.

The previous prime is 121551016201. The next prime is 121551016229. The reversal of 121551016209 is 902610155121.

It is not a de Polignac number, because 121551016209 - 2³ = 121551016201 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121551016209.

It is not an unprimeable number, because it can be changed into a prime (121551016201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3779254 + ... + 3811280.

It is an arithmetic number, because the mean of its divisors is an integer number (6129390528).

Almost surely, 2^121551016209 is an apocalyptic number.

It is an amenable number.

121551016209 is a deficient number, since it is larger than the sum of its proper divisors (74589480687).

121551016209 is a wasteful number, since it uses less digits than its factorization.

121551016209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42685.

The product of its (nonzero) digits is 5400, while the sum is 33.

The spelling of 121551016209 in words is "one hundred twenty-one billion, five hundred fifty-one million, sixteen thousand, two hundred nine".