21444100220500 has 96 divisors (see below), whose sum is σ = 49909964203008. Its totient is φ = 8030130944000.

The previous prime is 21444100220449. The next prime is 21444100220537. The reversal of 21444100220500 is 502200144412.

It is a Harshad number since it is a multiple of its sum of digits (25).

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, 19296781 + ... + 20377780.

It is an arithmetic number, because the mean of its divisors is an integer number (519895460448).

Almost surely, 2^{21444100220500} is an apocalyptic number.

21444100220500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21444100220500 is an abundant number, since it is smaller than the sum of its proper divisors (28465863982508).

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

21444100220500 is a wasteful number, since it uses less digits than its factorization.

21444100220500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39674650 (or 39674638 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 25.

Adding to 21444100220500 its reverse (502200144412), we get a palindrome (21946300364912).

The spelling of 21444100220500 in words is "twenty-one trillion, four hundred forty-four billion, one hundred million, two hundred twenty thousand, five hundred".