21101055 has 32 divisors (see below), whose sum is σ = 34801920. Its totient is φ = 10913280.

The previous prime is 21101033. The next prime is 21101123. The reversal of 21101055 is 55010112.

21101055 = 363² + 364² + ... + 480².

It is not a de Polignac number, because 21101055 - 2⁹ = 21100543 is a prime.

It is a super-2 number, since 2×21101055² = 890509044226050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 99900 + ... + 100110.

It is an arithmetic number, because the mean of its divisors is an integer number (1087560).

Almost surely, 2^21101055 is an apocalyptic number.

21101055 is a deficient number, since it is larger than the sum of its proper divisors (13700865).

21101055 is a wasteful number, since it uses less digits than its factorization.

21101055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391.

The product of its (nonzero) digits is 50, while the sum is 15.

The square root of 21101055 is about 4593.5884665477. The cubic root of 21101055 is about 276.3342542429.

Adding to 21101055 its reverse (55010112), we get a palindrome (76111167).

The spelling of 21101055 in words is "twenty-one million, one hundred one thousand, fifty-five".