21026254 has 4 divisors (see below), whose sum is σ = 31539384. Its totient is φ = 10513126.

The previous prime is 21026251. The next prime is 21026267. The reversal of 21026254 is 45262012.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21026251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5256562 + ... + 5256565.

It is an arithmetic number, because the mean of its divisors is an integer number (7884846).

Almost surely, 2^21026254 is an apocalyptic number.

21026254 is a deficient number, since it is larger than the sum of its proper divisors (10513130).

21026254 is a wasteful number, since it uses less digits than its factorization.

21026254 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10513129.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 21026254 is about 4585.4393464531. The cubic root of 21026254 is about 276.0073424498.

Adding to 21026254 its reverse (45262012), we get a palindrome (66288266).

The spelling of 21026254 in words is "twenty-one million, twenty-six thousand, two hundred fifty-four".