21406735756540 has 48 divisors (see below), whose sum is σ = 45460985572800. Its totient is φ = 8466160614912.

The previous prime is 21406735756531. The next prime is 21406735756603. The reversal of 21406735756540 is 4565753760412.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49351726 + ... + 49783594.

It is an arithmetic number, because the mean of its divisors is an integer number (947103866100).

Almost surely, 2^{21406735756540} is an apocalyptic number.

21406735756540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21406735756540 is an abundant number, since it is smaller than the sum of its proper divisors (24054249816260).

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

21406735756540 is a wasteful number, since it uses less digits than its factorization.

21406735756540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459814 (or 459812 counting only the distinct ones).

The product of its (nonzero) digits is 21168000, while the sum is 55.

The spelling of 21406735756540 in words is "twenty-one trillion, four hundred six billion, seven hundred thirty-five million, seven hundred fifty-six thousand, five hundred forty".