21545552523545 has 8 divisors (see below), whose sum is σ = 25855073986560. Its totient is φ = 17236168046640.

The previous prime is 21545552523487. The next prime is 21545552523563. The reversal of 21545552523545 is 54532525554512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21545552523545 - 2⁸ = 21545552523289 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33900185 + ... + 34529894.

It is an arithmetic number, because the mean of its divisors is an integer number (3231884248320).

Almost surely, 2^{21545552523545} is an apocalyptic number.

It is an amenable number.

21545552523545 is a deficient number, since it is larger than the sum of its proper divisors (4309521463015).

21545552523545 is an equidigital number, since it uses as much as digits as its factorization.

21545552523545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68493055.

The product of its digits is 30000000, while the sum is 53.

The spelling of 21545552523545 in words is "twenty-one trillion, five hundred forty-five billion, five hundred fifty-two million, five hundred twenty-three thousand, five hundred forty-five".