21901884018 has 32 divisors (see below), whose sum is σ = 50095393920. Its totient is φ = 6253438080.

The previous prime is 21901883999. The next prime is 21901884031. The reversal of 21901884018 is 81048810912.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a Curzon number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 113853 + ... + 238256.

It is an arithmetic number, because the mean of its divisors is an integer number (1565481060).

Almost surely, 2^21901884018 is an apocalyptic number.

21901884018 is an abundant number, since it is smaller than the sum of its proper divisors (28193509902).

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

21901884018 is a wasteful number, since it uses less digits than its factorization.

21901884018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353602.

The product of its (nonzero) digits is 36864, while the sum is 42.

The spelling of 21901884018 in words is "twenty-one billion, nine hundred one million, eight hundred eighty-four thousand, eighteen".