21204045481 has 16 divisors (see below), whose sum is σ = 23290122240. Its totient is φ = 19223493120.

The previous prime is 21204045463. The next prime is 21204045503. The reversal of 21204045481 is 18454040212.

It is a cyclic number.

It is not a de Polignac number, because 21204045481 - 2⁹ = 21204044969 is a prime.

It is a super-2 number, since 2×21204045481² (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 (21204045451) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 137481 + ... + 247606.

It is an arithmetic number, because the mean of its divisors is an integer number (1455632640).

Almost surely, 2^21204045481 is an apocalyptic number.

It is an amenable number.

21204045481 is a deficient number, since it is larger than the sum of its proper divisors (2086076759).

21204045481 is a wasteful number, since it uses less digits than its factorization.

21204045481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 385224.

The product of its (nonzero) digits is 10240, while the sum is 31.

Adding to 21204045481 its reverse (18454040212), we get a palindrome (39658085693).

The spelling of 21204045481 in words is "twenty-one billion, two hundred four million, forty-five thousand, four hundred eighty-one".