21271700513640 has 128 divisors (see below), whose sum is σ = 65026818662400. Its totient is φ = 5564770498560.

The previous prime is 21271700513629. The next prime is 21271700513663. The reversal of 21271700513640 is 4631500717212.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 55018521 + ... + 55403799.

It is an arithmetic number, because the mean of its divisors is an integer number (508022020800).

Almost surely, 2^{21271700513640} is an apocalyptic number.

21271700513640 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 21271700513640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32513409331200).

21271700513640 is an abundant number, since it is smaller than the sum of its proper divisors (43755118148760).

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

21271700513640 is a wasteful number, since it uses less digits than its factorization.

21271700513640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394027 (or 394023 counting only the distinct ones).

The product of its (nonzero) digits is 70560, while the sum is 39.

The spelling of 21271700513640 in words is "twenty-one trillion, two hundred seventy-one billion, seven hundred million, five hundred thirteen thousand, six hundred forty".