21369777 has 32 divisors (see below), whose sum is σ = 33855360. Its totient is φ = 11819520.

The previous prime is 21369773. The next prime is 21369797. The reversal of 21369777 is 77796312.

It is not a de Polignac number, because 21369777 - 2² = 21369773 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21369773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 46533 + ... + 46989.

It is an arithmetic number, because the mean of its divisors is an integer number (1057980).

Almost surely, 2^21369777 is an apocalyptic number.

It is an amenable number.

21369777 is a deficient number, since it is larger than the sum of its proper divisors (12485583).

21369777 is a wasteful number, since it uses less digits than its factorization.

21369777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 593.

The product of its digits is 111132, while the sum is 42.

The square root of 21369777 is about 4622.7456127284. The cubic root of 21369777 is about 277.5023488154.

The spelling of 21369777 in words is "twenty-one million, three hundred sixty-nine thousand, seven hundred seventy-seven".