21394937286240 has 768 divisors, whose sum is σ = 83011262939136. Its totient is φ = 4521000960000.

The previous prime is 21394937286211. The next prime is 21394937286251. The reversal of 21394937286240 is 4268273949312.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 732663640 + ... + 732692840.

It is an arithmetic number, because the mean of its divisors is an integer number (108087581952).

Almost surely, 2^{21394937286240} is an apocalyptic number.

21394937286240 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 21394937286240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41505631469568).

21394937286240 is an abundant number, since it is smaller than the sum of its proper divisors (61616325652896).

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

21394937286240 is a wasteful number, since it uses less digits than its factorization.

21394937286240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29471 (or 29463 counting only the distinct ones).

The product of its (nonzero) digits is 31352832, while the sum is 60.

The spelling of 21394937286240 in words is "twenty-one trillion, three hundred ninety-four billion, nine hundred thirty-seven million, two hundred eighty-six thousand, two hundred forty".