18821051 has 2 divisors, whose sum is σ = 18821052. Its totient is φ = 18821050.

The previous prime is 18821027. The next prime is 18821053. The reversal of 18821051 is 15012881.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18821051 is a prime.

Together with 18821053, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18821051.

It is not a weakly prime, because it can be changed into another prime (18821053) 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 as a sum of consecutive naturals, namely, 9410525 + 9410526.

It is an arithmetic number, because the mean of its divisors is an integer number (9410526).

Almost surely, 2^18821051 is an apocalyptic number.

18821051 is a deficient number, since it is larger than the sum of its proper divisors (1).

18821051 is an equidigital number, since it uses as much as digits as its factorization.

18821051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 640, while the sum is 26.

The square root of 18821051 is about 4338.3235241277. The cubic root of 18821051 is about 265.9997880037. Note that the first 3 decimals are identical.

The spelling of 18821051 in words is "eighteen million, eight hundred twenty-one thousand, fifty-one".