1011131221 has 4 divisors (see below), whose sum is σ = 1055093472. Its totient is φ = 967168972.

The previous prime is 1011131213. The next prime is 1011131239. The reversal of 1011131221 is 1221311101.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1221311101 = 109 ⋅11204689.

It is a cyclic number.

It is not a de Polignac number, because 1011131221 - 2³ = 1011131213 is a prime.

It is a super-3 number, since 3×1011131221³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1011171221) 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, 21981091 + ... + 21981136.

It is an arithmetic number, because the mean of its divisors is an integer number (263773368).

Almost surely, 2^1011131221 is an apocalyptic number.

It is an amenable number.

1011131221 is a deficient number, since it is larger than the sum of its proper divisors (43962251).

1011131221 is an equidigital number, since it uses as much as digits as its factorization.

1011131221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43962250.

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

The square root of 1011131221 is about 31798.2895923664. The cubic root of 1011131221 is about 1003.6967243893.

Adding to 1011131221 its reverse (1221311101), we get a palindrome (2232442322).

The spelling of 1011131221 in words is "one billion, eleven million, one hundred thirty-one thousand, two hundred twenty-one".