211643541515540 has 96 divisors (see below), whose sum is σ = 458312180272128. Its totient is φ = 82045678464000.

The previous prime is 211643541515513. The next prime is 211643541515587. The reversal of 211643541515540 is 45515145346112.

It is a super-2 number, since 2×211643541515540² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

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, 133830845 + ... + 135403035.

It is an arithmetic number, because the mean of its divisors is an integer number (4774085211168).

Almost surely, 2^{211643541515540} is an apocalyptic number.

211643541515540 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 211643541515540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (229156090136064).

211643541515540 is an abundant number, since it is smaller than the sum of its proper divisors (246668638756588).

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

211643541515540 is a wasteful number, since it uses less digits than its factorization.

211643541515540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1573329 (or 1573327 counting only the distinct ones).

The product of its (nonzero) digits is 1440000, while the sum is 47.

The spelling of 211643541515540 in words is "two hundred eleven trillion, six hundred forty-three billion, five hundred forty-one million, five hundred fifteen thousand, five hundred forty".