21531355340020 has 96 divisors (see below), whose sum is σ = 45610524731520. Its totient is φ = 8537660651520.

The previous prime is 21531355339973. The next prime is 21531355340071. The reversal of 21531355340020 is 2004355313512.

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, 3402012216 + ... + 3402018544.

It is an arithmetic number, because the mean of its divisors is an integer number (475109632620).

Almost surely, 2^{21531355340020} is an apocalyptic number.

21531355340020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21531355340020 is an abundant number, since it is smaller than the sum of its proper divisors (24079169391500).

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

21531355340020 is a wasteful number, since it uses less digits than its factorization.

21531355340020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9025 (or 9023 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 34.

The spelling of 21531355340020 in words is "twenty-one trillion, five hundred thirty-one billion, three hundred fifty-five million, three hundred forty thousand, twenty".