1993222821 has 4 divisors (see below), whose sum is σ = 2657630432. Its totient is φ = 1328815212.

The previous prime is 1993222813. The next prime is 1993222823. The reversal of 1993222821 is 1282223991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1282223991 = 3 ⋅427407997.

It is not a de Polignac number, because 1993222821 - 2³ = 1993222813 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 1993222821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1993222823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 332203801 + ... + 332203806.

It is an arithmetic number, because the mean of its divisors is an integer number (664407608).

Almost surely, 2^1993222821 is an apocalyptic number.

It is an amenable number.

1993222821 is a deficient number, since it is larger than the sum of its proper divisors (664407611).

1993222821 is an equidigital number, since it uses as much as digits as its factorization.

1993222821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 664407610.

The product of its digits is 31104, while the sum is 39.

The square root of 1993222821 is about 44645.5240869676. The cubic root of 1993222821 is about 1258.4963209937.

The spelling of 1993222821 in words is "one billion, nine hundred ninety-three million, two hundred twenty-two thousand, eight hundred twenty-one".