1221687472 has 20 divisors (see below), whose sum is σ = 2367672616. Its totient is φ = 610675200.

The previous prime is 1221687461. The next prime is 1221687487. The reversal of 1221687472 is 2747861221.

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 3 ways as a sum of consecutive naturals, for example, 66208 + ... + 82624.

Almost surely, 2^1221687472 is an apocalyptic number.

It is an amenable number.

1221687472 is a deficient number, since it is larger than the sum of its proper divisors (1145985144).

1221687472 is a wasteful number, since it uses less digits than its factorization.

1221687472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21076 (or 21070 counting only the distinct ones).

The product of its digits is 75264, while the sum is 40.

The square root of 1221687472 is about 34952.6461373098. The cubic root of 1221687472 is about 1069.0221572798.

The spelling of 1221687472 in words is "one billion, two hundred twenty-one million, six hundred eighty-seven thousand, four hundred seventy-two".