21256194044 has 6 divisors (see below), whose sum is σ = 37198339584. Its totient is φ = 10628097020.

The previous prime is 21256194041. The next prime is 21256194053. The reversal of 21256194044 is 44049165212.

It is a junction number, because it is equal to n+sod(n) for n = 21256193989 and 21256194007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21256194041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2657024252 + ... + 2657024259.

It is an arithmetic number, because the mean of its divisors is an integer number (6199723264).

Almost surely, 2^21256194044 is an apocalyptic number.

It is an amenable number.

21256194044 is a deficient number, since it is larger than the sum of its proper divisors (15942145540).

21256194044 is a wasteful number, since it uses less digits than its factorization.

21256194044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5314048515 (or 5314048513 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 38.

The spelling of 21256194044 in words is "twenty-one billion, two hundred fifty-six million, one hundred ninety-four thousand, forty-four".