21471529 has 4 divisors (see below), whose sum is σ = 21494484. Its totient is φ = 21448576.

The previous prime is 21471523. The next prime is 21471533. The reversal of 21471529 is 92517412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15840400 + 5631129 = 3980^2 + 2373^2 .

It is a cyclic number.

It is not a de Polignac number, because 21471529 - 2²³ = 13082921 is a prime.

It is a super-2 number, since 2×21471529² = 922053115195682, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21471529.

It is not an unprimeable number, because it can be changed into a prime (21471523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10012 + ... + 11965.

It is an arithmetic number, because the mean of its divisors is an integer number (5373621).

Almost surely, 2^21471529 is an apocalyptic number.

It is an amenable number.

21471529 is a deficient number, since it is larger than the sum of its proper divisors (22955).

21471529 is an equidigital number, since it uses as much as digits as its factorization.

21471529 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22954.

The product of its digits is 5040, while the sum is 31.

The square root of 21471529 is about 4633.7381238046. The cubic root of 21471529 is about 277.9420932476.

The spelling of 21471529 in words is "twenty-one million, four hundred seventy-one thousand, five hundred twenty-nine".