21618042501020 has 96 divisors (see below), whose sum is σ = 54615936883200. Its totient is φ = 7021551515904.

The previous prime is 21618042500993. The next prime is 21618042501043. The reversal of 21618042501020 is 2010524081612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 84255086 + ... + 84511274.

It is an arithmetic number, because the mean of its divisors is an integer number (568916009200).

Almost surely, 2^{21618042501020} is an apocalyptic number.

21618042501020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21618042501020 is an abundant number, since it is smaller than the sum of its proper divisors (32997894382180).

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

21618042501020 is a wasteful number, since it uses less digits than its factorization.

21618042501020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287947 (or 287945 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 32.

Adding to 21618042501020 its reverse (2010524081612), we get a palindrome (23628566582632).

The spelling of 21618042501020 in words is "twenty-one trillion, six hundred eighteen billion, forty-two million, five hundred one thousand, twenty".