21091054055 has 8 divisors (see below), whose sum is σ = 25614196272. Its totient is φ = 16669555648.

The previous prime is 21091054043. The next prime is 21091054123. The reversal of 21091054055 is 55045019012.

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

It is a cyclic number.

It is not a de Polignac number, because 21091054055 - 2²² = 21086859751 is a prime.

It is a super-2 number, since 2×21091054055² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25410494 + ... + 25411323.

It is an arithmetic number, because the mean of its divisors is an integer number (3201774534).

Almost surely, 2^21091054055 is an apocalyptic number.

21091054055 is a deficient number, since it is larger than the sum of its proper divisors (4523142217).

21091054055 is an equidigital number, since it uses as much as digits as its factorization.

21091054055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50821905.

The product of its (nonzero) digits is 9000, while the sum is 32.

The spelling of 21091054055 in words is "twenty-one billion, ninety-one million, fifty-four thousand, fifty-five".