1221426664 has 16 divisors (see below), whose sum is σ = 2302168320. Its totient is φ = 607515120.

The previous prime is 1221426649. The next prime is 1221426697. The reversal of 1221426664 is 4666241221.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 398154 + ... + 401209.

It is an arithmetic number, because the mean of its divisors is an integer number (143885520).

Almost surely, 2^1221426664 is an apocalyptic number.

It is an amenable number.

1221426664 is a deficient number, since it is larger than the sum of its proper divisors (1080741656).

1221426664 is a wasteful number, since it uses less digits than its factorization.

1221426664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 799560 (or 799556 counting only the distinct ones).

The product of its digits is 27648, while the sum is 34.

The square root of 1221426664 is about 34948.9150618442. The cubic root of 1221426664 is about 1068.9460796195.

Adding to 1221426664 its reverse (4666241221), we get a palindrome (5887667885).

The spelling of 1221426664 in words is "one billion, two hundred twenty-one million, four hundred twenty-six thousand, six hundred sixty-four".