21506065123040 has 96 divisors (see below), whose sum is σ = 51646701587040. Its totient is φ = 8460468172800.

The previous prime is 21506065123009. The next prime is 21506065123043. The reversal of 21506065123040 is 4032156060512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21506065123043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 91812470 + ... + 92046410.

It is an arithmetic number, because the mean of its divisors is an integer number (537986474865).

Almost surely, 2^{21506065123040} is an apocalyptic number.

21506065123040 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 21506065123040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25823350793520).

21506065123040 is an abundant number, since it is smaller than the sum of its proper divisors (30140636464000).

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

21506065123040 is a wasteful number, since it uses less digits than its factorization.

21506065123040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243436 (or 243428 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 35.

The spelling of 21506065123040 in words is "twenty-one trillion, five hundred six billion, sixty-five million, one hundred twenty-three thousand, forty".