21000255904305 has 64 divisors (see below), whose sum is σ = 38967103365120. Its totient is φ = 10710394630848.

The previous prime is 21000255904267. The next prime is 21000255904307. The reversal of 21000255904305 is 50340955200012.

It is a happy number.

21000255904305 is a `hidden beast` number, since 2 + 1 + 0 + 0 + 0 + 25 + 590 + 43 + 0 + 5 = 666.

It is not a de Polignac number, because 21000255904305 - 2¹⁸ = 21000255642161 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21000255904305.

It is not an unprimeable number, because it can be changed into a prime (21000255904307) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11119212 + ... + 12870018.

It is an arithmetic number, because the mean of its divisors is an integer number (608860990080).

Almost surely, 2^{21000255904305} is an apocalyptic number.

It is an amenable number.

21000255904305 is a deficient number, since it is larger than the sum of its proper divisors (17966847460815).

21000255904305 is a wasteful number, since it uses less digits than its factorization.

21000255904305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1754707 (or 1754701 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

The spelling of 21000255904305 in words is "twenty-one trillion, two hundred fifty-five million, nine hundred four thousand, three hundred five".