21266427 has 16 divisors (see below), whose sum is σ = 34899200. Its totient is φ = 11217312.

The previous prime is 21266411. The next prime is 21266449. The reversal of 21266427 is 72466212.

It is not a de Polignac number, because 21266427 - 2⁴ = 21266411 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21266394 and 21266403.

It is not an unprimeable number, because it can be changed into a prime (21266407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38677 + ... + 39222.

It is an arithmetic number, because the mean of its divisors is an integer number (2181200).

Almost surely, 2^21266427 is an apocalyptic number.

21266427 is a deficient number, since it is larger than the sum of its proper divisors (13632773).

21266427 is a wasteful number, since it uses less digits than its factorization.

21266427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77922.

The product of its digits is 8064, while the sum is 30.

The square root of 21266427 is about 4611.5536427543. The cubic root of 21266427 is about 277.0542669770.

The spelling of 21266427 in words is "twenty-one million, two hundred sixty-six thousand, four hundred twenty-seven".