811550121 has 4 divisors (see below), whose sum is σ = 1082066832. Its totient is φ = 541033412.

The previous prime is 811550111. The next prime is 811550143. The reversal of 811550121 is 121055118.

811550121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 811550121 - 2⁷ = 811549993 is a prime.

It is a super-2 number, since 2×811550121² = 1317227197790229282, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 811550091 and 811550100.

It is not an unprimeable number, because it can be changed into a prime (811550111) 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, 135258351 + ... + 135258356.

It is an arithmetic number, because the mean of its divisors is an integer number (270516708).

Almost surely, 2^811550121 is an apocalyptic number.

It is an amenable number.

811550121 is a deficient number, since it is larger than the sum of its proper divisors (270516711).

811550121 is a wasteful number, since it uses less digits than its factorization.

811550121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270516710.

The product of its (nonzero) digits is 400, while the sum is 24.

The square root of 811550121 is about 28487.7187749388. The cubic root of 811550121 is about 932.7640131533.

The spelling of 811550121 in words is "eight hundred eleven million, five hundred fifty thousand, one hundred twenty-one".