21116777 has 16 divisors (see below), whose sum is σ = 23647680. Its totient is φ = 18696000.

The previous prime is 21116773. The next prime is 21116801. The reversal of 21116777 is 77761112.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21116777 - 2² = 21116773 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21116773) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 92099 + ... + 92327.

It is an arithmetic number, because the mean of its divisors is an integer number (1477980).

Almost surely, 2^21116777 is an apocalyptic number.

It is an amenable number.

21116777 is a deficient number, since it is larger than the sum of its proper divisors (2530903).

21116777 is a wasteful number, since it uses less digits than its factorization.

21116777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 424.

The product of its digits is 4116, while the sum is 32.

The square root of 21116777 is about 4595.2994461732. The cubic root of 21116777 is about 276.4028676934.

Adding to 21116777 its reverse (77761112), we get a palindrome (98877889).

It can be divided in two parts, 2111 and 6777, that added together give a palindrome (8888).

The spelling of 21116777 in words is "twenty-one million, one hundred sixteen thousand, seven hundred seventy-seven".