21077311 has 4 divisors (see below), whose sum is σ = 21087000. Its totient is φ = 21067624.

The previous prime is 21077299. The next prime is 21077317. The reversal of 21077311 is 11377012.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21077311 - 2⁷ = 21077183 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 (21077317) 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, 105 + ... + 6493.

It is an arithmetic number, because the mean of its divisors is an integer number (5271750).

Almost surely, 2^21077311 is an apocalyptic number.

21077311 is a deficient number, since it is larger than the sum of its proper divisors (9689).

21077311 is an equidigital number, since it uses as much as digits as its factorization.

21077311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9688.

The product of its (nonzero) digits is 294, while the sum is 22.

The square root of 21077311 is about 4591.0032672609. The cubic root of 21077311 is about 276.2305668032.

The spelling of 21077311 in words is "twenty-one million, seventy-seven thousand, three hundred eleven".