1226666221 has 4 divisors (see below), whose sum is σ = 1338181344. Its totient is φ = 1115151100.

The previous prime is 1226666179. The next prime is 1226666261.

1226666221 is nontrivially palindromic in base 10.

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.

It is a cyclic number.

It is not a de Polignac number, because 1226666221 - 2¹⁹ = 1226141933 is a prime.

It is a super-3 number, since 3×1226666221³ (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 (1226666261) 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, 55757545 + ... + 55757566.

It is an arithmetic number, because the mean of its divisors is an integer number (334545336).

Almost surely, 2^1226666221 is an apocalyptic number.

1226666221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1226666221 is a deficient number, since it is larger than the sum of its proper divisors (111515123).

1226666221 is a wasteful number, since it uses less digits than its factorization.

1226666221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111515122.

The product of its digits is 20736, while the sum is 34.

The square root of 1226666221 is about 35023.7950684959. The cubic root of 1226666221 is about 1070.4723861145.

It can be divided in two parts, 12266 and 66221, that added together give a palindrome (78487).

The spelling of 1226666221 in words is "one billion, two hundred twenty-six million, six hundred sixty-six thousand, two hundred twenty-one".