21518539929040 has 80 divisors (see below), whose sum is σ = 62375819656320. Its totient is φ = 6707077378560.

The previous prime is 21518539929023. The next prime is 21518539929053. The reversal of 21518539929040 is 4092993581512.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

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, 1746628575 + ... + 1746640894.

It is an arithmetic number, because the mean of its divisors is an integer number (779697745704).

Almost surely, 2^{21518539929040} is an apocalyptic number.

21518539929040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21518539929040 is an abundant number, since it is smaller than the sum of its proper divisors (40857279727280).

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

21518539929040 is a wasteful number, since it uses less digits than its factorization.

21518539929040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3493269500 (or 3493269494 counting only the distinct ones).

The product of its (nonzero) digits is 6998400, while the sum is 58.

The spelling of 21518539929040 in words is "twenty-one trillion, five hundred eighteen billion, five hundred thirty-nine million, nine hundred twenty-nine thousand, forty".