1221423412 has 24 divisors (see below), whose sum is σ = 2468975040. Its totient is φ = 522533760.

The previous prime is 1221423409. The next prime is 1221423473. The reversal of 1221423412 is 2143241221.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 815712 + ... + 817207.

It is an arithmetic number, because the mean of its divisors is an integer number (102873960).

Almost surely, 2^1221423412 is an apocalyptic number.

It is an amenable number.

1221423412 is an abundant number, since it is smaller than the sum of its proper divisors (1247551628).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221423412 is a wasteful number, since it uses less digits than its factorization.

1221423412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1632951 (or 1632949 counting only the distinct ones).

The product of its digits is 768, while the sum is 22.

The square root of 1221423412 is about 34948.8685367638. The cubic root of 1221423412 is about 1068.9451309431.

Adding to 1221423412 its reverse (2143241221), we get a palindrome (3364664633).

The spelling of 1221423412 in words is "one billion, two hundred twenty-one million, four hundred twenty-three thousand, four hundred twelve".