121156009 has 4 divisors (see below), whose sum is σ = 130475716. Its totient is φ = 111836304.

The previous prime is 121156003. The next prime is 121156037. The reversal of 121156009 is 900651121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 900651121 = 163 ⋅5525467.

It can be written as a sum of positive squares in 2 ways, for example, as 15642025 + 105513984 = 3955^2 + 10272^2 .

It is a cyclic number.

It is not a de Polignac number, because 121156009 - 2¹¹ = 121153961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121156003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4659834 + ... + 4659859.

It is an arithmetic number, because the mean of its divisors is an integer number (32618929).

Almost surely, 2^121156009 is an apocalyptic number.

It is an amenable number.

121156009 is a deficient number, since it is larger than the sum of its proper divisors (9319707).

121156009 is an equidigital number, since it uses as much as digits as its factorization.

121156009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9319706.

The product of its (nonzero) digits is 540, while the sum is 25.

The square root of 121156009 is about 11007.0890338908. The cubic root of 121156009 is about 494.8212244248.

The spelling of 121156009 in words is "one hundred twenty-one million, one hundred fifty-six thousand, nine".