21207254 has 8 divisors (see below), whose sum is σ = 31833648. Its totient is φ = 10596040.

The previous prime is 21207239. The next prime is 21207259. The reversal of 21207254 is 45270212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21207259) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 824 + ... + 6564.

It is an arithmetic number, because the mean of its divisors is an integer number (3979206).

Almost surely, 2^21207254 is an apocalyptic number.

21207254 is a deficient number, since it is larger than the sum of its proper divisors (10626394).

21207254 is a wasteful number, since it uses less digits than its factorization.

21207254 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7590.

The product of its (nonzero) digits is 1120, while the sum is 23.

The square root of 21207254 is about 4605.1334399776. The cubic root of 21207254 is about 276.7970640622.

Adding to 21207254 its reverse (45270212), we get a palindrome (66477466).

The spelling of 21207254 in words is "twenty-one million, two hundred seven thousand, two hundred fifty-four".