121942735209 has 27 divisors (see below), whose sum is σ = 180397677213. Its totient is φ = 79375238712.

The previous prime is 121942735177. The next prime is 121942735261. The reversal of 121942735209 is 902537249121.

The square root of 121942735209 is 349203.

It is a perfect power (a square), and thus also a powerful number.

121942735209 is a `hidden beast` number, since 1 + 2 + 19 + 42 + 73 + 520 + 9 = 666.

It is not a de Polignac number, because 121942735209 - 2⁵ = 121942735177 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121942735279) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 45045834 + ... + 45048540.

Almost surely, 2^121942735209 is an apocalyptic number.

121942735209 is the 349203-rd square number.

121942735209 is the 174602-nd centered octagonal number.

It is an amenable number.

121942735209 is a deficient number, since it is larger than the sum of its proper divisors (58454942004).

121942735209 is an frugal number, since it uses more digits than its factorization.

121942735209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5506 (or 2753 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 45.

The spelling of 121942735209 in words is "one hundred twenty-one billion, nine hundred forty-two million, seven hundred thirty-five thousand, two hundred nine".