21065277 has 4 divisors (see below), whose sum is σ = 28087040. Its totient is φ = 14043516.

The previous prime is 21065273. The next prime is 21065287. The reversal of 21065277 is 77256012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21065277 - 2² = 21065273 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21065273) 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 3 ways as a sum of consecutive naturals, for example, 3510877 + ... + 3510882.

It is an arithmetic number, because the mean of its divisors is an integer number (7021760).

Almost surely, 2^21065277 is an apocalyptic number.

It is an amenable number.

21065277 is a deficient number, since it is larger than the sum of its proper divisors (7021763).

21065277 is an equidigital number, since it uses as much as digits as its factorization.

21065277 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7021762.

The product of its (nonzero) digits is 5880, while the sum is 30.

The square root of 21065277 is about 4589.6924733581. The cubic root of 21065277 is about 276.1779859105.

The spelling of 21065277 in words is "twenty-one million, sixty-five thousand, two hundred seventy-seven".