1221334540 has 24 divisors (see below), whose sum is σ = 2593624320. Its totient is φ = 483043968.

The previous prime is 1221334511. The next prime is 1221334567. The reversal of 1221334540 is 454331221.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 341292 + ... + 344851.

It is an arithmetic number, because the mean of its divisors is an integer number (108067680).

Almost surely, 2^1221334540 is an apocalyptic number.

1221334540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221334540 is an abundant number, since it is smaller than the sum of its proper divisors (1372289780).

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

1221334540 is a wasteful number, since it uses less digits than its factorization.

1221334540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 686241 (or 686239 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 1221334540 is about 34947.5970561640. The cubic root of 1221334540 is about 1068.9192044722.

Adding to 1221334540 its reverse (454331221), we get a palindrome (1675665761).

The spelling of 1221334540 in words is "one billion, two hundred twenty-one million, three hundred thirty-four thousand, five hundred forty".