21377267 has 4 divisors (see below), whose sum is σ = 21727776. Its totient is φ = 21026760.

The previous prime is 21377249. The next prime is 21377269. The reversal of 21377267 is 76277312.

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 21377267 - 2¹² = 21373171 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21377269) 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, 175163 + ... + 175284.

It is an arithmetic number, because the mean of its divisors is an integer number (5431944).

Almost surely, 2^21377267 is an apocalyptic number.

21377267 is a deficient number, since it is larger than the sum of its proper divisors (350509).

21377267 is an equidigital number, since it uses as much as digits as its factorization.

21377267 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350508.

The product of its digits is 24696, while the sum is 35.

The square root of 21377267 is about 4623.5556663676. Note that the first 3 decimals coincide. The cubic root of 21377267 is about 277.5347660903.

The spelling of 21377267 in words is "twenty-one million, three hundred seventy-seven thousand, two hundred sixty-seven".