21152135 has 8 divisors (see below), whose sum is σ = 25688880. Its totient is φ = 16717504.

The previous prime is 21152099. The next prime is 21152143. The reversal of 21152135 is 53125112.

It is a happy number.

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 21152135 - 2²⁴ = 4374919 is a prime.

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, 25070 + ... + 25899.

It is an arithmetic number, because the mean of its divisors is an integer number (3211110).

Almost surely, 2^21152135 is an apocalyptic number.

21152135 is a deficient number, since it is larger than the sum of its proper divisors (4536745).

21152135 is an equidigital number, since it uses as much as digits as its factorization.

21152135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51057.

The product of its digits is 300, while the sum is 20.

The square root of 21152135 is about 4599.1450292418. The cubic root of 21152135 is about 276.5570516232.

Adding to 21152135 its reverse (53125112), we get a palindrome (74277247).

The spelling of 21152135 in words is "twenty-one million, one hundred fifty-two thousand, one hundred thirty-five".