21530204545 has 8 divisors (see below), whose sum is σ = 25928191080. Its totient is φ = 17162866560.

The previous prime is 21530204543. The next prime is 21530204551. The reversal of 21530204545 is 54540203512.

It can be written as a sum of positive squares in 4 ways, for example, as 1814674801 + 19715529744 = 42599^2 + 140412^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21530204545 - 2¹ = 21530204543 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21530204543) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7660590 + ... + 7663399.

It is an arithmetic number, because the mean of its divisors is an integer number (3241023885).

Almost surely, 2^21530204545 is an apocalyptic number.

It is an amenable number.

21530204545 is a deficient number, since it is larger than the sum of its proper divisors (4397986535).

21530204545 is a wasteful number, since it uses less digits than its factorization.

21530204545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15324275.

The product of its (nonzero) digits is 24000, while the sum is 31.

The spelling of 21530204545 in words is "twenty-one billion, five hundred thirty million, two hundred four thousand, five hundred forty-five".