1011123121 has 4 divisors (see below), whose sum is σ = 1011690100. Its totient is φ = 1010556144.

The previous prime is 1011123103. The next prime is 1011123137. The reversal of 1011123121 is 1213211101.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1213211101 = 2621 ⋅462881.

It can be written as a sum of positive squares in 2 ways, for example, as 904806400 + 106316721 = 30080^2 + 10311^2 .

It is a cyclic number.

It is not a de Polignac number, because 1011123121 - 2⁷ = 1011122993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1011123151) 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 3 ways as a sum of consecutive naturals, for example, 280806 + ... + 284383.

It is an arithmetic number, because the mean of its divisors is an integer number (252922525).

Almost surely, 2^1011123121 is an apocalyptic number.

It is an amenable number.

1011123121 is a deficient number, since it is larger than the sum of its proper divisors (566979).

1011123121 is an equidigital number, since it uses as much as digits as its factorization.

1011123121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 566978.

The product of its (nonzero) digits is 12, while the sum is 13.

The square root of 1011123121 is about 31798.1622267703. The cubic root of 1011123121 is about 1003.6940442343.

Adding to 1011123121 its reverse (1213211101), we get a palindrome (2224334222).

The spelling of 1011123121 in words is "one billion, eleven million, one hundred twenty-three thousand, one hundred twenty-one".