1221691803 has 8 divisors (see below), whose sum is σ = 1681468416. Its totient is φ = 788188200.

The previous prime is 1221691799. The next prime is 1221691829. The reversal of 1221691803 is 3081961221.

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

It is not a de Polignac number, because 1221691803 - 2² = 1221691799 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (1221691843) 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, 6568143 + ... + 6568328.

It is an arithmetic number, because the mean of its divisors is an integer number (210183552).

Almost surely, 2^1221691803 is an apocalyptic number.

1221691803 is a deficient number, since it is larger than the sum of its proper divisors (459776613).

1221691803 is a wasteful number, since it uses less digits than its factorization.

1221691803 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13136505.

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 1221691803 is about 34952.7080925069. The cubic root of 1221691803 is about 1069.0234205405.

The spelling of 1221691803 in words is "one billion, two hundred twenty-one million, six hundred ninety-one thousand, eight hundred three".