1221219747 has 20 divisors (see below), whose sum is σ = 1990137336. Its totient is φ = 740132640.

The previous prime is 1221219733. The next prime is 1221219749. The reversal of 1221219747 is 7479121221.

It is not a de Polignac number, because 1221219747 - 2⁸ = 1221219491 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221219749) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 684418 + ... + 686199.

Almost surely, 2^1221219747 is an apocalyptic number.

1221219747 is a deficient number, since it is larger than the sum of its proper divisors (768917589).

1221219747 is a wasteful number, since it uses less digits than its factorization.

1221219747 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1370640 (or 1370631 counting only the distinct ones).

The product of its digits is 14112, while the sum is 36.

The square root of 1221219747 is about 34945.9546585867. The cubic root of 1221219747 is about 1068.8857142523.

The spelling of 1221219747 in words is "one billion, two hundred twenty-one million, two hundred nineteen thousand, seven hundred forty-seven".