21769807 has 16 divisors (see below), whose sum is σ = 23284800. Its totient is φ = 20321280.

The previous prime is 21769757. The next prime is 21769817. The reversal of 21769807 is 70896712.

It is a cyclic number.

It is not a de Polignac number, because 21769807 - 2¹⁵ = 21737039 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21769807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21769817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 199669 + ... + 199777.

It is an arithmetic number, because the mean of its divisors is an integer number (1455300).

Almost surely, 2^21769807 is an apocalyptic number.

21769807 is a deficient number, since it is larger than the sum of its proper divisors (1514993).

21769807 is a wasteful number, since it uses less digits than its factorization.

21769807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306.

The product of its (nonzero) digits is 42336, while the sum is 40.

The square root of 21769807 is about 4665.8125766044. The cubic root of 21769807 is about 279.2232169195.

The spelling of 21769807 in words is "twenty-one million, seven hundred sixty-nine thousand, eight hundred seven".