1221021219 has 16 divisors (see below), whose sum is σ = 1793620224. Its totient is φ = 732684000.

The previous prime is 1221021203. The next prime is 1221021223. The reversal of 1221021219 is 9121201221.

It is not a de Polignac number, because 1221021219 - 2⁴ = 1221021203 is a prime.

It is a super-2 number, since 2×1221021219² = 2981785634496491922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221021195 and 1221021204.

It is not an unprimeable number, because it can be changed into a prime (1221021229) 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, 179839 + ... + 186504.

It is an arithmetic number, because the mean of its divisors is an integer number (112101264).

Almost surely, 2^1221021219 is an apocalyptic number.

1221021219 is a deficient number, since it is larger than the sum of its proper divisors (572599005).

1221021219 is a wasteful number, since it uses less digits than its factorization.

1221021219 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366458.

The product of its (nonzero) digits is 144, while the sum is 21.

The square root of 1221021219 is about 34943.1140426837. The cubic root of 1221021219 is about 1068.8277898579.

It can be divided in two parts, 122102 and 1219, that added together give a palindrome (123321).

The spelling of 1221021219 in words is "one billion, two hundred twenty-one million, twenty-one thousand, two hundred nineteen".