1821328051 has 4 divisors (see below), whose sum is σ = 1839361104. Its totient is φ = 1803295000.

The previous prime is 1821328039. The next prime is 1821328063. The reversal of 1821328051 is 1508231281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1508231281 = 2791 ⋅540391.

It is an interprime number because it is at equal distance from previous prime (1821328039) and next prime (1821328063).

It is a cyclic number.

It is not a de Polignac number, because 1821328051 - 2⁹ = 1821327539 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1821328001) 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, 9016375 + ... + 9016576.

It is an arithmetic number, because the mean of its divisors is an integer number (459840276).

Almost surely, 2^1821328051 is an apocalyptic number.

1821328051 is a deficient number, since it is larger than the sum of its proper divisors (18033053).

1821328051 is a wasteful number, since it uses less digits than its factorization.

1821328051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18033052.

The product of its (nonzero) digits is 3840, while the sum is 31.

The square root of 1821328051 is about 42677.0201747966. The cubic root of 1821328051 is about 1221.2260475392.

It can be divided in two parts, 18213 and 28051, that added together give a palindrome (46264).

The spelling of 1821328051 in words is "one billion, eight hundred twenty-one million, three hundred twenty-eight thousand, fifty-one".