21542342520 has 256 divisors, whose sum is σ = 66977280000. Its totient is φ = 5541120000.

The previous prime is 21542342483. The next prime is 21542342531. The reversal of 21542342520 is 2524324512.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 142664445 + ... + 142664595.

It is an arithmetic number, because the mean of its divisors is an integer number (261630000).

Almost surely, 2^21542342520 is an apocalyptic number.

21542342520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21542342520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33488640000).

21542342520 is an abundant number, since it is smaller than the sum of its proper divisors (45434937480).

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

21542342520 is a wasteful number, since it uses less digits than its factorization.

21542342520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 494 (or 490 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 30.

The spelling of 21542342520 in words is "twenty-one billion, five hundred forty-two million, three hundred forty-two thousand, five hundred twenty".