1121220021 has 16 divisors (see below), whose sum is σ = 1505433600. Its totient is φ = 742255728.

The previous prime is 1121220017. The next prime is 1121220041. The reversal of 1121220021 is 1200221211.

It is not a de Polignac number, because 1121220021 - 2² = 1121220017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1121219979 and 1121220006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1121220041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 636540 + ... + 638298.

It is an arithmetic number, because the mean of its divisors is an integer number (94089600).

Almost surely, 2^1121220021 is an apocalyptic number.

It is an amenable number.

1121220021 is a deficient number, since it is larger than the sum of its proper divisors (384213579).

1121220021 is a wasteful number, since it uses less digits than its factorization.

1121220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3128.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 1121220021 is about 33484.6236502667. The cubic root of 1121220021 is about 1038.8757640016.

Adding to 1121220021 its reverse (1200221211), we get a palindrome (2321441232).

The spelling of 1121220021 in words is "one billion, one hundred twenty-one million, two hundred twenty thousand, twenty-one".