21355445155 has 16 divisors (see below), whose sum is σ = 27980548704. Its totient is φ = 15517716480.

The previous prime is 21355445149. The next prime is 21355445201. The reversal of 21355445155 is 55154455312.

It is not a de Polignac number, because 21355445155 - 2³ = 21355445147 is a prime.

It is a Duffinian number.

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 15 ways as a sum of consecutive naturals, for example, 104964 + ... + 231793.

It is an arithmetic number, because the mean of its divisors is an integer number (1748784294).

Almost surely, 2^21355445155 is an apocalyptic number.

21355445155 is a deficient number, since it is larger than the sum of its proper divisors (6625103549).

21355445155 is a wasteful number, since it uses less digits than its factorization.

21355445155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337926.

The product of its digits is 300000, while the sum is 40.

The spelling of 21355445155 in words is "twenty-one billion, three hundred fifty-five million, four hundred forty-five thousand, one hundred fifty-five".