21534475 has 12 divisors (see below), whose sum is σ = 26855920. Its totient is φ = 17128800.

The previous prime is 21534451. The next prime is 21534479. The reversal of 21534475 is 57443512.

It is a de Polignac number, because none of the positive numbers 2^k-21534475 is a prime.

It is a super-2 number, since 2×21534475² = 927467227051250, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21534479) 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 11 ways as a sum of consecutive naturals, for example, 2146 + ... + 6904.

Almost surely, 2^21534475 is an apocalyptic number.

21534475 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21534475 is a deficient number, since it is larger than the sum of its proper divisors (5321445).

21534475 is a wasteful number, since it uses less digits than its factorization.

21534475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4950 (or 4945 counting only the distinct ones).

The product of its digits is 16800, while the sum is 31.

The square root of 21534475 is about 4640.5252935417. The cubic root of 21534475 is about 278.2134335625.

Adding to 21534475 its reverse (57443512), we get a palindrome (78977987).

The spelling of 21534475 in words is "twenty-one million, five hundred thirty-four thousand, four hundred seventy-five".