1221455431 has 8 divisors (see below), whose sum is σ = 1396162080. Its totient is φ = 1046802048.

The previous prime is 1221455429. The next prime is 1221455441. The reversal of 1221455431 is 1345541221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221455431 - 2¹ = 1221455429 is a prime.

It is a super-2 number, since 2×1221455431² = 2983906739838791522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221455431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221455441) 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 7 ways as a sum of consecutive naturals, for example, 74115 + ... + 89083.

It is an arithmetic number, because the mean of its divisors is an integer number (174520260).

Almost surely, 2^1221455431 is an apocalyptic number.

1221455431 is a deficient number, since it is larger than the sum of its proper divisors (174706649).

1221455431 is a wasteful number, since it uses less digits than its factorization.

1221455431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26633.

The product of its digits is 4800, while the sum is 28.

The square root of 1221455431 is about 34949.3266172612. The cubic root of 1221455431 is about 1068.9544714811.

Adding to 1221455431 its reverse (1345541221), we get a palindrome (2566996652).

The spelling of 1221455431 in words is "one billion, two hundred twenty-one million, four hundred fifty-five thousand, four hundred thirty-one".