21100135 has 24 divisors (see below), whose sum is σ = 29893536. Its totient is φ = 14253120.

The previous prime is 21100129. The next prime is 21100141. The reversal of 21100135 is 53100112.

It is an interprime number because it is at equal distance from previous prime (21100129) and next prime (21100141).

It is not a de Polignac number, because 21100135 - 2⁵ = 21100103 is a prime.

It is a super-3 number, since 3×21100135³ (a number of 23 digits) contains 333 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 23 ways as a sum of consecutive naturals, for example, 16789 + ... + 18001.

It is an arithmetic number, because the mean of its divisors is an integer number (1245564).

Almost surely, 2^21100135 is an apocalyptic number.

21100135 is a deficient number, since it is larger than the sum of its proper divisors (8793401).

21100135 is a wasteful number, since it uses less digits than its factorization.

21100135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1303 (or 1296 counting only the distinct ones).

The product of its (nonzero) digits is 30, while the sum is 13.

The square root of 21100135 is about 4593.4883258805. The cubic root of 21100135 is about 276.3302381528.

Adding to 21100135 its reverse (53100112), we get a palindrome (74200247).

The spelling of 21100135 in words is "twenty-one million, one hundred thousand, one hundred thirty-five".