1221946403 has 4 divisors (see below), whose sum is σ = 1224730320. Its totient is φ = 1219162488.

The previous prime is 1221946399. The next prime is 1221946409. The reversal of 1221946403 is 3046491221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3046491221 = 8663 ⋅351667.

It is a cyclic number.

It is not a de Polignac number, because 1221946403 - 2² = 1221946399 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221946403.

It is not an unprimeable number, because it can be changed into a prime (1221946409) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1391300 + ... + 1392177.

It is an arithmetic number, because the mean of its divisors is an integer number (306182580).

Almost surely, 2^1221946403 is an apocalyptic number.

1221946403 is a deficient number, since it is larger than the sum of its proper divisors (2783917).

1221946403 is an equidigital number, since it uses as much as digits as its factorization.

1221946403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2783916.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 1221946403 is about 34956.3499667800. The cubic root of 1221946403 is about 1069.0976767093.

The spelling of 1221946403 in words is "one billion, two hundred twenty-one million, nine hundred forty-six thousand, four hundred three".