21005574489 has 9 divisors (see below), whose sum is σ = 30342013429. Its totient is φ = 14003426460.

The previous prime is 21005574467. The next prime is 21005574497. The reversal of 21005574489 is 98447550012.

The square root of 21005574489 is 144933.

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

21005574489 is a `hidden beast` number, since 2 + 10 + 0 + 557 + 4 + 4 + 89 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 21005574489 - 2¹⁵ = 21005541721 is a prime.

It is a super-2 number, since 2×21005574489² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21005574589) 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, 410644 + ... + 458954.

Almost surely, 2^21005574489 is an apocalyptic number.

21005574489 is the 144933-rd square number.

21005574489 is the 72467-th centered octagonal number.

It is an amenable number.

21005574489 is a deficient number, since it is larger than the sum of its proper divisors (9336438940).

21005574489 is an frugal number, since it uses more digits than its factorization.

21005574489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96628 (or 48314 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The spelling of 21005574489 in words is "twenty-one billion, five million, five hundred seventy-four thousand, four hundred eighty-nine".