1221101331 has 8 divisors (see below), whose sum is σ = 1652435904. Its totient is φ = 801917160.

The previous prime is 1221101311. The next prime is 1221101353. The reversal of 1221101331 is 1331011221.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221101331 - 2²⁶ = 1153992467 is a prime.

It is a super-2 number, since 2×1221101331² = 2982176921139943122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1221101331.

It is not an unprimeable number, because it can be changed into a prime (1221101311) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3037365 + ... + 3037766.

It is an arithmetic number, because the mean of its divisors is an integer number (206554488).

Almost surely, 2^1221101331 is an apocalyptic number.

1221101331 is a deficient number, since it is larger than the sum of its proper divisors (431334573).

1221101331 is an equidigital number, since it uses as much as digits as its factorization.

1221101331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6075201.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 1221101331 is about 34944.2603441538. The cubic root of 1221101331 is about 1068.8511648432.

Adding to 1221101331 its reverse (1331011221), we get a palindrome (2552112552).

The spelling of 1221101331 in words is "one billion, two hundred twenty-one million, one hundred one thousand, three hundred thirty-one".