21769481 has 8 divisors (see below), whose sum is σ = 22375584. Its totient is φ = 21168000.

The previous prime is 21769453. The next prime is 21769487. The reversal of 21769481 is 18496712.

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 21769481 - 2⁶ = 21769417 is a prime.

It is a super-2 number, since 2×21769481² = 947820606018722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21769487) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9785 + ... + 11801.

It is an arithmetic number, because the mean of its divisors is an integer number (2796948).

Almost surely, 2^21769481 is an apocalyptic number.

It is an amenable number.

21769481 is a deficient number, since it is larger than the sum of its proper divisors (606103).

21769481 is a wasteful number, since it uses less digits than its factorization.

21769481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2311.

The product of its digits is 24192, while the sum is 38.

The square root of 21769481 is about 4665.7776415084. Note that the first 3 decimals coincide. The cubic root of 21769481 is about 279.2218231355.

The spelling of 21769481 in words is "twenty-one million, seven hundred sixty-nine thousand, four hundred eighty-one".