21480023 has 4 divisors (see below), whose sum is σ = 22003968. Its totient is φ = 20956080.

The previous prime is 21480007. The next prime is 21480049. The reversal of 21480023 is 32008412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21480023 - 2⁴ = 21480007 is a prime.

It is a super-2 number, since 2×21480023² = 922782776161058, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21479977 and 21480004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21480073) 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 3 ways as a sum of consecutive naturals, for example, 261911 + ... + 261992.

It is an arithmetic number, because the mean of its divisors is an integer number (5500992).

Almost surely, 2^21480023 is an apocalyptic number.

21480023 is a deficient number, since it is larger than the sum of its proper divisors (523945).

21480023 is an equidigital number, since it uses as much as digits as its factorization.

21480023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 523944.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 21480023 is about 4634.6545718101. The cubic root of 21480023 is about 277.9787391225.

Adding to 21480023 its reverse (32008412), we get a palindrome (53488435).

The spelling of 21480023 in words is "twenty-one million, four hundred eighty thousand, twenty-three".