21455515302020 has 48 divisors (see below), whose sum is σ = 46151313183360. Its totient is φ = 8374092013056.

The previous prime is 21455515301921. The next prime is 21455515302031. The reversal of 21455515302020 is 2020351555412.

It is a happy 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, 11844485 + ... + 13535244.

It is an arithmetic number, because the mean of its divisors is an integer number (961485691320).

Almost surely, 2^{21455515302020} is an apocalyptic number.

21455515302020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21455515302020 is an abundant number, since it is smaller than the sum of its proper divisors (24695797881340).

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

21455515302020 is a wasteful number, since it uses less digits than its factorization.

21455515302020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25380764 (or 25380762 counting only the distinct ones).

The product of its (nonzero) digits is 60000, while the sum is 35.

Adding to 21455515302020 its reverse (2020351555412), we get a palindrome (23475866857432).

The spelling of 21455515302020 in words is "twenty-one trillion, four hundred fifty-five billion, five hundred fifteen million, three hundred two thousand, twenty".