21088404855 has 192 divisors, whose sum is σ = 45682790400. Its totient is φ = 8785013760.

The previous prime is 21088404823. The next prime is 21088404881. The reversal of 21088404855 is 55840488012.

It is not a de Polignac number, because 21088404855 - 2⁵ = 21088404823 is a prime.

It is a super-3 number, since 3×21088404855³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21088404855.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 17158381 + ... + 17159609.

It is an arithmetic number, because the mean of its divisors is an integer number (237931200).

Almost surely, 2^21088404855 is an apocalyptic number.

21088404855 is an abundant number, since it is smaller than the sum of its proper divisors (24594385545).

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

21088404855 is a wasteful number, since it uses less digits than its factorization.

21088404855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1374 (or 1371 counting only the distinct ones).

The product of its (nonzero) digits is 409600, while the sum is 45.

The spelling of 21088404855 in words is "twenty-one billion, eighty-eight million, four hundred four thousand, eight hundred fifty-five".