21254115 has 8 divisors (see below), whose sum is σ = 34006608. Its totient is φ = 11335520.

The previous prime is 21254099. The next prime is 21254117. The reversal of 21254115 is 51145212.

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

It is not a de Polignac number, because 21254115 - 2⁴ = 21254099 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21254091 and 21254100.

It is not an unprimeable number, because it can be changed into a prime (21254117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 708456 + ... + 708485.

It is an arithmetic number, because the mean of its divisors is an integer number (4250826).

Almost surely, 2^21254115 is an apocalyptic number.

21254115 is a deficient number, since it is larger than the sum of its proper divisors (12752493).

21254115 is a wasteful number, since it uses less digits than its factorization.

21254115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1416949.

The product of its digits is 400, while the sum is 21.

The square root of 21254115 is about 4610.2185414577. The cubic root of 21254115 is about 277.0007906592. Note that the first 3 decimals are identical.

Adding to 21254115 its reverse (51145212), we get a palindrome (72399327).

The spelling of 21254115 in words is "twenty-one million, two hundred fifty-four thousand, one hundred fifteen".