21383777 has 2 divisors, whose sum is σ = 21383778. Its totient is φ = 21383776.

The previous prime is 21383753. The next prime is 21383833. The reversal of 21383777 is 77738312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21381376 + 2401 = 4624^2 + 49^2 .

It is a cyclic number.

It is not a de Polignac number, because 21383777 - 2¹² = 21379681 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21383777.

It is not a weakly prime, because it can be changed into another prime (21383177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10691888 + 10691889.

It is an arithmetic number, because the mean of its divisors is an integer number (10691889).

Almost surely, 2^21383777 is an apocalyptic number.

It is an amenable number.

21383777 is a deficient number, since it is larger than the sum of its proper divisors (1).

21383777 is an equidigital number, since it uses as much as digits as its factorization.

21383777 is an evil number, because the sum of its binary digits is even.

The product of its digits is 49392, while the sum is 38.

The square root of 21383777 is about 4624.2596164143. The cubic root of 21383777 is about 277.5629357024.

The spelling of 21383777 in words is "twenty-one million, three hundred eighty-three thousand, seven hundred seventy-seven".