1221113421 has 32 divisors (see below), whose sum is σ = 1978128000. Its totient is φ = 738339840.

The previous prime is 1221113419. The next prime is 1221113429. The reversal of 1221113421 is 1243111221.

It is not a de Polignac number, because 1221113421 - 2¹ = 1221113419 is a prime.

It is a super-2 number, since 2×1221113421² = 2982235973892646482, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221113394 and 1221113403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221113429) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 128775 + ... + 137931.

It is an arithmetic number, because the mean of its divisors is an integer number (61816500).

Almost surely, 2^1221113421 is an apocalyptic number.

1221113421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221113421 is a deficient number, since it is larger than the sum of its proper divisors (757014579).

1221113421 is a wasteful number, since it uses less digits than its factorization.

1221113421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9626 (or 9620 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

The square root of 1221113421 is about 34944.4333335082. The cubic root of 1221113421 is about 1068.8546923604.

Adding to 1221113421 its reverse (1243111221), we get a palindrome (2464224642).

The spelling of 1221113421 in words is "one billion, two hundred twenty-one million, one hundred thirteen thousand, four hundred twenty-one".