1221230431 has 4 divisors (see below), whose sum is σ = 1241250664. Its totient is φ = 1201210200.

The previous prime is 1221230429. The next prime is 1221230447. The reversal of 1221230431 is 1340321221.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1221230431 - 2¹ = 1221230429 is a prime.

It is a super-2 number, since 2×1221230431² = 2982807531200891522, 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 = 1221230399 and 1221230408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221230531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10010025 + ... + 10010146.

It is an arithmetic number, because the mean of its divisors is an integer number (310312666).

Almost surely, 2^1221230431 is an apocalyptic number.

1221230431 is a deficient number, since it is larger than the sum of its proper divisors (20020233).

1221230431 is an equidigital number, since it uses as much as digits as its factorization.

1221230431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20020232.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 1221230431 is about 34946.1075228701. The cubic root of 1221230431 is about 1068.8888313385. Note that the first 4 decimals are identical.

Adding to 1221230431 its reverse (1340321221), we get a palindrome (2561551652).

The spelling of 1221230431 in words is "one billion, two hundred twenty-one million, two hundred thirty thousand, four hundred thirty-one".