21008025253894 has 16 divisors (see below), whose sum is σ = 36021008302848. Its totient is φ = 9001626713352.

The previous prime is 21008025253861. The next prime is 21008025253921. The reversal of 21008025253894 is 49835252080012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 150984744 + ... + 151123819.

It is an arithmetic number, because the mean of its divisors is an integer number (2251313018928).

Almost surely, 2^{21008025253894} is an apocalyptic number.

21008025253894 is a deficient number, since it is larger than the sum of its proper divisors (15012983048954).

21008025253894 is a wasteful number, since it uses less digits than its factorization.

21008025253894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302113539.

The product of its (nonzero) digits is 1382400, while the sum is 49.

The spelling of 21008025253894 in words is "twenty-one trillion, eight billion, twenty-five million, two hundred fifty-three thousand, eight hundred ninety-four".