21254506 has 32 divisors (see below), whose sum is σ = 40602240. Its totient is φ = 8116416.

The previous prime is 21254491. The next prime is 21254567. The reversal of 21254506 is 60545212.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3265 + ... + 7291.

It is an arithmetic number, because the mean of its divisors is an integer number (1268820).

Almost surely, 2^21254506 is an apocalyptic number.

21254506 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21254506 is a deficient number, since it is larger than the sum of its proper divisors (19347734).

21254506 is a wasteful number, since it uses less digits than its factorization.

21254506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4078.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 21254506 is about 4610.2609470615. The cubic root of 21254506 is about 277.0024892581.

Adding to 21254506 its reverse (60545212), we get a palindrome (81799718).

The spelling of 21254506 in words is "twenty-one million, two hundred fifty-four thousand, five hundred six".