1221963279 has 8 divisors (see below), whose sum is σ = 1651603632. Its totient is φ = 803482560.

The previous prime is 1221963277. The next prime is 1221963287. The reversal of 1221963279 is 9723691221.

1221963279 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221963279 - 2¹ = 1221963277 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221963279.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221963277) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2789652 + ... + 2790089.

It is an arithmetic number, because the mean of its divisors is an integer number (206450454).

Almost surely, 2^1221963279 is an apocalyptic number.

1221963279 is a deficient number, since it is larger than the sum of its proper divisors (429640353).

1221963279 is an equidigital number, since it uses as much as digits as its factorization.

1221963279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5579817.

The product of its digits is 81648, while the sum is 42.

The square root of 1221963279 is about 34956.5913527049. The cubic root of 1221963279 is about 1069.1025983680.

The spelling of 1221963279 in words is "one billion, two hundred twenty-one million, nine hundred sixty-three thousand, two hundred seventy-nine".