21255310515340 has 48 divisors (see below), whose sum is σ = 49519305884160. Its totient is φ = 7598200364480.

The previous prime is 21255310515287. The next prime is 21255310515389. The reversal of 21255310515340 is 4351501355212.

It is a super-3 number, since 3×21255310515340³ (a number of 41 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21255310515340.

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, 818758612 + ... + 818784571.

It is an arithmetic number, because the mean of its divisors is an integer number (1031652205920).

Almost surely, 2^{21255310515340} is an apocalyptic number.

21255310515340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21255310515340 is an abundant number, since it is smaller than the sum of its proper divisors (28263995368820).

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

21255310515340 is a wasteful number, since it uses less digits than its factorization.

21255310515340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1637543262 (or 1637543260 counting only the distinct ones).

The product of its (nonzero) digits is 90000, while the sum is 37.

The spelling of 21255310515340 in words is "twenty-one trillion, two hundred fifty-five billion, three hundred ten million, five hundred fifteen thousand, three hundred forty".