21548465 has 4 divisors (see below), whose sum is σ = 25858164. Its totient is φ = 17238768.

The previous prime is 21548399. The next prime is 21548491. The reversal of 21548465 is 56484512.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5234944 + 16313521 = 2288^2 + 4039^2 .

It is a cyclic number.

It is not a de Polignac number, because 21548465 - 2⁸ = 21548209 is a prime.

It is a super-3 number, since 3×21548465³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2154842 + ... + 2154851.

It is an arithmetic number, because the mean of its divisors is an integer number (6464541).

Almost surely, 2^21548465 is an apocalyptic number.

It is an amenable number.

21548465 is a deficient number, since it is larger than the sum of its proper divisors (4309699).

21548465 is an equidigital number, since it uses as much as digits as its factorization.

21548465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4309698.

The product of its digits is 38400, while the sum is 35.

The square root of 21548465 is about 4642.0324212569. The cubic root of 21548465 is about 278.2736681921.

The spelling of 21548465 in words is "twenty-one million, five hundred forty-eight thousand, four hundred sixty-five".