21800028181854 has 64 divisors (see below), whose sum is σ = 48109332547584. Its totient is φ = 6543052338816.

The previous prime is 21800028181853. The next prime is 21800028181913. The reversal of 21800028181854 is 45818182000812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21800028181853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1754094 + ... + 6832049.

It is an arithmetic number, because the mean of its divisors is an integer number (751708321056).

Almost surely, 2^{21800028181854} is an apocalyptic number.

21800028181854 is an abundant number, since it is smaller than the sum of its proper divisors (26309304365730).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21800028181854 is a wasteful number, since it uses less digits than its factorization.

21800028181854 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8586961.

The product of its (nonzero) digits is 327680, while the sum is 48.

The spelling of 21800028181854 in words is "twenty-one trillion, eight hundred billion, twenty-eight million, one hundred eighty-one thousand, eight hundred fifty-four".