21455515530555 has 8 divisors (see below), whose sum is σ = 34328824848912. Its totient is φ = 11442941616288.

The previous prime is 21455515530517. The next prime is 21455515530587. The reversal of 21455515530555 is 55503551555412.

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

It is not a de Polignac number, because 21455515530555 - 2¹¹ = 21455515528507 is a prime.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 21455515530498 and 21455515530507.

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, 715183851004 + ... + 715183851033.

It is an arithmetic number, because the mean of its divisors is an integer number (4291103106114).

Almost surely, 2^{21455515530555} is an apocalyptic number.

21455515530555 is a deficient number, since it is larger than the sum of its proper divisors (12873309318357).

21455515530555 is a wasteful number, since it uses less digits than its factorization.

21455515530555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1430367702045.

The product of its (nonzero) digits is 9375000, while the sum is 51.

The spelling of 21455515530555 in words is "twenty-one trillion, four hundred fifty-five billion, five hundred fifteen million, five hundred thirty thousand, five hundred fifty-five".