21504254545 has 8 divisors (see below), whose sum is σ = 25806902760. Its totient is φ = 17202205440.

The previous prime is 21504254537. The next prime is 21504254581. The reversal of 21504254545 is 54545240512.

It can be written as a sum of positive squares in 4 ways, for example, as 605504449 + 20898750096 = 24607^2 + 144564^2 .

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

It is not a de Polignac number, because 21504254545 - 2³ = 21504254537 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66610 + ... + 217819.

It is an arithmetic number, because the mean of its divisors is an integer number (3225862845).

Almost surely, 2^21504254545 is an apocalyptic number.

It is an amenable number.

21504254545 is a deficient number, since it is larger than the sum of its proper divisors (4302648215).

21504254545 is a wasteful number, since it uses less digits than its factorization.

21504254545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299555.

The product of its (nonzero) digits is 160000, while the sum is 37.

The spelling of 21504254545 in words is "twenty-one billion, five hundred four million, two hundred fifty-four thousand, five hundred forty-five".