21541415266540 has 144 divisors (see below), whose sum is σ = 49158624846240. Its totient is φ = 7925507266560.

The previous prime is 21541415266531. The next prime is 21541415266561. The reversal of 21541415266540 is 4566251414512.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1434461112 + ... + 1434476128.

It is an arithmetic number, because the mean of its divisors is an integer number (341379339210).

Almost surely, 2^{21541415266540} is an apocalyptic number.

21541415266540 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 21541415266540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24579312423120).

21541415266540 is an abundant number, since it is smaller than the sum of its proper divisors (27617209579700).

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

21541415266540 is a wasteful number, since it uses less digits than its factorization.

21541415266540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16532 (or 16517 counting only the distinct ones).

The product of its (nonzero) digits is 1152000, while the sum is 46.

The spelling of 21541415266540 in words is "twenty-one trillion, five hundred forty-one billion, four hundred fifteen million, two hundred sixty-six thousand, five hundred forty".