21769913 has 8 divisors (see below), whose sum is σ = 23836896. Its totient is φ = 19717600.

The previous prime is 21769907. The next prime is 21769931. The reversal of 21769913 is 31996712.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21769913 - 2⁶ = 21769849 is a prime.

It is a super-2 number, since 2×21769913² = 947858224055138, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21769903) 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 7 ways as a sum of consecutive naturals, for example, 431 + ... + 6612.

It is an arithmetic number, because the mean of its divisors is an integer number (2979612).

Almost surely, 2^21769913 is an apocalyptic number.

It is an amenable number.

21769913 is a deficient number, since it is larger than the sum of its proper divisors (2066983).

21769913 is a wasteful number, since it uses less digits than its factorization.

21769913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7335.

The product of its digits is 20412, while the sum is 38.

The square root of 21769913 is about 4665.8239358124. The cubic root of 21769913 is about 279.2236701100.

It can be divided in two parts, 217699 and 13, that added together give a palindrome (217712).

The spelling of 21769913 in words is "twenty-one million, seven hundred sixty-nine thousand, nine hundred thirteen".