21254873 has 4 divisors (see below), whose sum is σ = 21270288. Its totient is φ = 21239460.

The previous prime is 21254867. The next prime is 21254887. The reversal of 21254873 is 37845212.

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 21254873 - 2⁸ = 21254617 is a prime.

It is a super-2 number, since 2×21254873² = 903539252492258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21254813) 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, 5411 + ... + 8472.

It is an arithmetic number, because the mean of its divisors is an integer number (5317572).

Almost surely, 2^21254873 is an apocalyptic number.

It is an amenable number.

21254873 is a deficient number, since it is larger than the sum of its proper divisors (15415).

21254873 is a wasteful number, since it uses less digits than its factorization.

21254873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15414.

The product of its digits is 13440, while the sum is 32.

The square root of 21254873 is about 4610.3007494089. The cubic root of 21254873 is about 277.0040835761.

It can be divided in two parts, 212 and 54873, that multiplied together give a triangular number (11633076 = T₄₈₂₃).

The spelling of 21254873 in words is "twenty-one million, two hundred fifty-four thousand, eight hundred seventy-three".