21464689 has 9 divisors (see below), whose sum is σ = 22197409. Its totient is φ = 20755840.

The previous prime is 21464687. The next prime is 21464711. The reversal of 21464689 is 98646412.

The square root of 21464689 is 4633.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 18879025 + 2585664 = 4345^2 + 1608^2 .

It is not a de Polignac number, because 21464689 - 2¹ = 21464687 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21464683) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 189897 + ... + 190009.

Almost surely, 2^21464689 is an apocalyptic number.

21464689 is the 4633-rd square number.

21464689 is the 2317-th centered octagonal number.

It is an amenable number.

21464689 is a deficient number, since it is larger than the sum of its proper divisors (732720).

21464689 is an frugal number, since it uses more digits than its factorization.

21464689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308 (or 154 counting only the distinct ones).

The product of its digits is 82944, while the sum is 40.

The cubic root of 21464689 is about 277.9125762404.

Multiplying 21464689 by its product of digits (82944), we get a square (1780367164416 = 1334304²).

The spelling of 21464689 in words is "twenty-one million, four hundred sixty-four thousand, six hundred eighty-nine".