1221531423 has 8 divisors (see below), whose sum is σ = 1861381248. Its totient is φ = 698017944.

The previous prime is 1221531419. The next prime is 1221531427. The reversal of 1221531423 is 3241351221.

It is an interprime number because it is at equal distance from previous prime (1221531419) and next prime (1221531427).

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

It is not a de Polignac number, because 1221531423 - 2² = 1221531419 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221531393 and 1221531402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221531427) 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, 29084061 + ... + 29084102.

It is an arithmetic number, because the mean of its divisors is an integer number (232672656).

Almost surely, 2^1221531423 is an apocalyptic number.

1221531423 is a deficient number, since it is larger than the sum of its proper divisors (639849825).

1221531423 is an equidigital number, since it uses as much as digits as its factorization.

1221531423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58168173.

The product of its digits is 1440, while the sum is 24.

The square root of 1221531423 is about 34950.4137743747. The cubic root of 1221531423 is about 1068.9766391076.

Adding to 1221531423 its reverse (3241351221), we get a palindrome (4462882644).

The spelling of 1221531423 in words is "one billion, two hundred twenty-one million, five hundred thirty-one thousand, four hundred twenty-three".