21699777 has 12 divisors (see below), whose sum is σ = 31802960. Its totient is φ = 13151160.

The previous prime is 21699763. The next prime is 21699779. The reversal of 21699777 is 77799612.

It is not a de Polignac number, because 21699777 - 2⁸ = 21699521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21699779) 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 11 ways as a sum of consecutive naturals, for example, 29527 + ... + 30252.

Almost surely, 2^21699777 is an apocalyptic number.

It is an amenable number.

21699777 is a deficient number, since it is larger than the sum of its proper divisors (10103183).

21699777 is a wasteful number, since it uses less digits than its factorization.

21699777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59804 (or 59793 counting only the distinct ones).

The product of its digits is 333396, while the sum is 48.

The square root of 21699777 is about 4658.3019438418. The cubic root of 21699777 is about 278.9234897668.

The spelling of 21699777 in words is "twenty-one million, six hundred ninety-nine thousand, seven hundred seventy-seven".