21426875 has 10 divisors (see below), whose sum is σ = 26775804. Its totient is φ = 17141000.

The previous prime is 21426841. The next prime is 21426901. The reversal of 21426875 is 57862412.

It is not a de Polignac number, because 21426875 - 2¹⁰ = 21425851 is a prime.

It is a super-2 number, since 2×21426875² = 918221944531250, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 16517 + ... + 17766.

Almost surely, 2^21426875 is an apocalyptic number.

21426875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21426875 is a deficient number, since it is larger than the sum of its proper divisors (5348929).

21426875 is an frugal number, since it uses more digits than its factorization.

21426875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34303 (or 34288 counting only the distinct ones).

The product of its digits is 26880, while the sum is 35.

The square root of 21426875 is about 4628.9172600080. The cubic root of 21426875 is about 277.7492822621.

The spelling of 21426875 in words is "twenty-one million, four hundred twenty-six thousand, eight hundred seventy-five".