21534873 has 16 divisors (see below), whose sum is σ = 29701056. Its totient is φ = 13870080.

The previous prime is 21534841. The next prime is 21534889. The reversal of 21534873 is 37843512.

It is not a de Polignac number, because 21534873 - 2⁵ = 21534841 is a prime.

It is a super-2 number, since 2×21534873² = 927501510252258, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21534833) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11653 + ... + 13373.

It is an arithmetic number, because the mean of its divisors is an integer number (1856316).

Almost surely, 2^21534873 is an apocalyptic number.

It is an amenable number.

21534873 is a deficient number, since it is larger than the sum of its proper divisors (8166183).

21534873 is a wasteful number, since it uses less digits than its factorization.

21534873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1864.

The product of its digits is 20160, while the sum is 33.

The square root of 21534873 is about 4640.5681764198. The cubic root of 21534873 is about 278.2151475315.

The spelling of 21534873 in words is "twenty-one million, five hundred thirty-four thousand, eight hundred seventy-three".