21151514 has 4 divisors (see below), whose sum is σ = 31727274. Its totient is φ = 10575756.

The previous prime is 21151489. The next prime is 21151561. The reversal of 21151514 is 41515112.

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

It can be written as a sum of positive squares in only one way, i.e., 20403289 + 748225 = 4517^2 + 865^2 .

It is a Curzon number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 5287877 + ... + 5287880.

Almost surely, 2^21151514 is an apocalyptic number.

21151514 is a deficient number, since it is larger than the sum of its proper divisors (10575760).

21151514 is a wasteful number, since it uses less digits than its factorization.

21151514 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10575759.

The product of its digits is 200, while the sum is 20.

The square root of 21151514 is about 4599.0775161982. The cubic root of 21151514 is about 276.5543451414.

Adding to 21151514 its reverse (41515112), we get a palindrome (62666626).

The spelling of 21151514 in words is "twenty-one million, one hundred fifty-one thousand, five hundred fourteen".