21254172 has 24 divisors (see below), whose sum is σ = 49752192. Its totient is φ = 7062000.

The previous prime is 21254171. The next prime is 21254173. The reversal of 21254172 is 27145212.

It is an interprime number because it is at equal distance from previous prime (21254171) and next prime (21254173).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21254171) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1297 + ... + 6647.

It is an arithmetic number, because the mean of its divisors is an integer number (2073008).

Almost surely, 2^21254172 is an apocalyptic number.

It is an amenable number.

21254172 is an abundant number, since it is smaller than the sum of its proper divisors (28498020).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21254172 is a wasteful number, since it uses less digits than its factorization.

21254172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5689 (or 5687 counting only the distinct ones).

The product of its digits is 1120, while the sum is 24.

The square root of 21254172 is about 4610.2247233730. The cubic root of 21254172 is about 277.0010382824.

Adding to 21254172 its reverse (27145212), we get a palindrome (48399384).

The spelling of 21254172 in words is "twenty-one million, two hundred fifty-four thousand, one hundred seventy-two".