1221144431 has 16 divisors (see below), whose sum is σ = 1327886784. Its totient is φ = 1116274944.

The previous prime is 1221144371. The next prime is 1221144461. The reversal of 1221144431 is 1344411221.

It is a cyclic number.

It is not a de Polignac number, because 1221144431 - 2²² = 1216950127 is a prime.

It is a super-2 number, since 2×1221144431² = 2982387442724627522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221144397 and 1221144406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221144461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1376270 + ... + 1377156.

It is an arithmetic number, because the mean of its divisors is an integer number (82992924).

Almost surely, 2^1221144431 is an apocalyptic number.

1221144431 is a deficient number, since it is larger than the sum of its proper divisors (106742353).

1221144431 is a wasteful number, since it uses less digits than its factorization.

1221144431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1810.

The product of its digits is 768, while the sum is 23.

The square root of 1221144431 is about 34944.8770351249. The cubic root of 1221144431 is about 1068.8637400877.

Adding to 1221144431 its reverse (1344411221), we get a palindrome (2565555652).

The spelling of 1221144431 in words is "one billion, two hundred twenty-one million, one hundred forty-four thousand, four hundred thirty-one".