21439469 has 4 divisors (see below), whose sum is σ = 21534144. Its totient is φ = 21344796.

The previous prime is 21439463. The next prime is 21439471. The reversal of 21439469 is 96493412.

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 not a de Polignac number, because 21439469 - 2⁸ = 21439213 is a prime.

It is a super-2 number, since 2×21439469² = 919301662003922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21439463) 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, 46997 + ... + 47450.

It is an arithmetic number, because the mean of its divisors is an integer number (5383536).

Almost surely, 2^21439469 is an apocalyptic number.

It is an amenable number.

21439469 is a deficient number, since it is larger than the sum of its proper divisors (94675).

21439469 is an equidigital number, since it uses as much as digits as its factorization.

21439469 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94674.

The product of its digits is 46656, while the sum is 38.

The square root of 21439469 is about 4630.2774214943. The cubic root of 21439469 is about 277.8036888481.

The spelling of 21439469 in words is "twenty-one million, four hundred thirty-nine thousand, four hundred sixty-nine".