21540332340 has 36 divisors (see below), whose sum is σ = 65339008644. Its totient is φ = 5744088576.

The previous prime is 21540332339. The next prime is 21540332377. The reversal of 21540332340 is 4323304512.

21540332340 is a `hidden beast` number, since 21 + 5 + 403 + 3 + 234 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 3526934544 + 18013397796 = 59388^2 + 134214^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 59834077 + ... + 59834436.

Almost surely, 2^21540332340 is an apocalyptic number.

21540332340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21540332340 is an abundant number, since it is smaller than the sum of its proper divisors (43798676304).

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

21540332340 is a wasteful number, since it uses less digits than its factorization.

21540332340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119668528 (or 119668523 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 27.

Adding to 21540332340 its reverse (4323304512), we get a palindrome (25863636852).

The spelling of 21540332340 in words is "twenty-one billion, five hundred forty million, three hundred thirty-two thousand, three hundred forty".