21764469 has 8 divisors (see below), whose sum is σ = 29140672. Its totient is φ = 14448960.

The previous prime is 21764467. The next prime is 21764489. The reversal of 21764469 is 96446712.

It is a happy number.

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

It is not a de Polignac number, because 21764469 - 2¹ = 21764467 is a prime.

It is a super-2 number, since 2×21764469² = 947384221703922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21764467) 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, 14329 + ... + 15774.

It is an arithmetic number, because the mean of its divisors is an integer number (3642584).

Almost surely, 2^21764469 is an apocalyptic number.

It is an amenable number.

21764469 is a deficient number, since it is larger than the sum of its proper divisors (7376203).

21764469 is a wasteful number, since it uses less digits than its factorization.

21764469 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30347.

The product of its digits is 72576, while the sum is 39.

The square root of 21764469 is about 4665.2405082696. The cubic root of 21764469 is about 279.2003930244.

The spelling of 21764469 in words is "twenty-one million, seven hundred sixty-four thousand, four hundred sixty-nine".