1221611814 has 32 divisors (see below), whose sum is σ = 2716086240. Its totient is φ = 406994976.

The previous prime is 1221611779. The next prime is 1221611837. The reversal of 1221611814 is 4181161221.

It is a happy number.

1221611814 is a `hidden beast` number, since 12 + 21 + 611 + 8 + 14 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 129192 + ... + 138324.

It is an arithmetic number, because the mean of its divisors is an integer number (84877695).

Almost surely, 2^1221611814 is an apocalyptic number.

1221611814 is an abundant number, since it is smaller than the sum of its proper divisors (1494474426).

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

1221611814 is a wasteful number, since it uses less digits than its factorization.

1221611814 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11621 (or 11615 counting only the distinct ones).

The product of its digits is 768, while the sum is 27.

The square root of 1221611814 is about 34951.5638276744. The cubic root of 1221611814 is about 1069.0000889658. Note that the first 4 decimals are identical.

The spelling of 1221611814 in words is "one billion, two hundred twenty-one million, six hundred eleven thousand, eight hundred fourteen".