21495953 has 4 divisors (see below), whose sum is σ = 21519600. Its totient is φ = 21472308.

The previous prime is 21495941. The next prime is 21495959. The reversal of 21495953 is 35959412.

21495953 is nontrivially palindromic in base 8.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21495953 - 2¹⁰ = 21494929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21495959) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10403 + ... + 12296.

It is an arithmetic number, because the mean of its divisors is an integer number (5379900).

Almost surely, 2^21495953 is an apocalyptic number.

It is an amenable number.

21495953 is a deficient number, since it is larger than the sum of its proper divisors (23647).

21495953 is an equidigital number, since it uses as much as digits as its factorization.

21495953 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23646.

The product of its digits is 48600, while the sum is 38.

The square root of 21495953 is about 4636.3728279766. The cubic root of 21495953 is about 278.0474402762.

The spelling of 21495953 in words is "twenty-one million, four hundred ninety-five thousand, nine hundred fifty-three".