21777713 has 2 divisors, whose sum is σ = 21777714. Its totient is φ = 21777712.

The previous prime is 21777709. The next prime is 21777727. The reversal of 21777713 is 31777712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16056049 + 5721664 = 4007^2 + 2392^2 .

It is a cyclic number.

It is not a de Polignac number, because 21777713 - 2² = 21777709 is a prime.

It is not a weakly prime, because it can be changed into another prime (21777773) 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 as a sum of consecutive naturals, namely, 10888856 + 10888857.

It is an arithmetic number, because the mean of its divisors is an integer number (10888857).

Almost surely, 2^21777713 is an apocalyptic number.

It is an amenable number.

21777713 is a deficient number, since it is larger than the sum of its proper divisors (1).

21777713 is an equidigital number, since it uses as much as digits as its factorization.

21777713 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14406, while the sum is 35.

The square root of 21777713 is about 4666.6597261853. The cubic root of 21777713 is about 279.2570140584.

Subtracting 21777713 from its reverse (31777712), we obtain a palindrome (9999999).

The spelling of 21777713 in words is "twenty-one million, seven hundred seventy-seven thousand, seven hundred thirteen".