1221646475 has 24 divisors (see below), whose sum is σ = 1732606368. Its totient is φ = 837043200.

The previous prime is 1221646471. The next prime is 1221646483. The reversal of 1221646475 is 5746461221.

It is a happy number.

It is not a de Polignac number, because 1221646475 - 2² = 1221646471 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221646471) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 351245 + ... + 354705.

It is an arithmetic number, because the mean of its divisors is an integer number (72191932).

Almost surely, 2^1221646475 is an apocalyptic number.

1221646475 is a deficient number, since it is larger than the sum of its proper divisors (510959893).

1221646475 is a wasteful number, since it uses less digits than its factorization.

1221646475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5495 (or 5490 counting only the distinct ones).

The product of its digits is 80640, while the sum is 38.

The square root of 1221646475 is about 34952.0596674931. The cubic root of 1221646475 is about 1069.0101991774.

The spelling of 1221646475 in words is "one billion, two hundred twenty-one million, six hundred forty-six thousand, four hundred seventy-five".