1221231340 has 24 divisors (see below), whose sum is σ = 2930955552. Its totient is φ = 418707840.

The previous prime is 1221231337. The next prime is 1221231367. The reversal of 1221231340 is 431321221.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4361401 + ... + 4361680.

It is an arithmetic number, because the mean of its divisors is an integer number (122123148).

Almost surely, 2^1221231340 is an apocalyptic number.

1221231340 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221231340 is an abundant number, since it is smaller than the sum of its proper divisors (1709724212).

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

1221231340 is a wasteful number, since it uses less digits than its factorization.

1221231340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8723097 (or 8723095 counting only the distinct ones).

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

The square root of 1221231340 is about 34946.1205286080. The cubic root of 1221231340 is about 1068.8890965409.

Adding to 1221231340 its reverse (431321221), we get a palindrome (1652552561).

The spelling of 1221231340 in words is "one billion, two hundred twenty-one million, two hundred thirty-one thousand, three hundred forty".