21266151 has 4 divisors (see below), whose sum is σ = 28354872. Its totient is φ = 14177432.

The previous prime is 21266129. The next prime is 21266171. The reversal of 21266151 is 15166212.

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

It is a cyclic number.

It is not a de Polignac number, because 21266151 - 2⁶ = 21266087 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21266171) 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, 3544356 + ... + 3544361.

It is an arithmetic number, because the mean of its divisors is an integer number (7088718).

Almost surely, 2^21266151 is an apocalyptic number.

21266151 is a deficient number, since it is larger than the sum of its proper divisors (7088721).

21266151 is an equidigital number, since it uses as much as digits as its factorization.

21266151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7088720.

The product of its digits is 720, while the sum is 24.

The square root of 21266151 is about 4611.5237178182. The cubic root of 21266151 is about 277.0530684163.

The spelling of 21266151 in words is "twenty-one million, two hundred sixty-six thousand, one hundred fifty-one".