21490535 has 8 divisors (see below), whose sum is σ = 28133136. Its totient is φ = 15629440.

The previous prime is 21490531. The next prime is 21490541. The reversal of 21490535 is 53509412.

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

It is not a de Polignac number, because 21490535 - 2² = 21490531 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21490498 and 21490507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21490531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 195314 + ... + 195423.

It is an arithmetic number, because the mean of its divisors is an integer number (3516642).

Almost surely, 2^21490535 is an apocalyptic number.

21490535 is a deficient number, since it is larger than the sum of its proper divisors (6642601).

21490535 is a wasteful number, since it uses less digits than its factorization.

21490535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 390753.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 21490535 is about 4635.7884981953. The cubic root of 21490535 is about 278.0240779311.

Adding to 21490535 its reverse (53509412), we get a palindrome (74999947).

The spelling of 21490535 in words is "twenty-one million, four hundred ninety thousand, five hundred thirty-five".