21769693 has 4 divisors (see below), whose sum is σ = 23748768. Its totient is φ = 19790620.

The previous prime is 21769681. The next prime is 21769717. The reversal of 21769693 is 39696712.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21769693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21769603) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 989521 + ... + 989542.

It is an arithmetic number, because the mean of its divisors is an integer number (5937192).

Almost surely, 2^21769693 is an apocalyptic number.

It is an amenable number.

21769693 is a deficient number, since it is larger than the sum of its proper divisors (1979075).

21769693 is a wasteful number, since it uses less digits than its factorization.

21769693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1979074.

The product of its digits is 122472, while the sum is 43.

The square root of 21769693 is about 4665.8003600669. The cubic root of 21769693 is about 279.2227295242. Note that the first 3 decimals are identical.

The spelling of 21769693 in words is "twenty-one million, seven hundred sixty-nine thousand, six hundred ninety-three".