21494551856 has 20 divisors (see below), whose sum is σ = 41750607552. Its totient is φ = 10720201536.

The previous prime is 21494551853. The next prime is 21494551867. The reversal of 21494551856 is 65815549412.

It is a hoax number, since the sum of its digits (50) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21494551853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1685600 + ... + 1698303.

Almost surely, 2^21494551856 is an apocalyptic number.

It is an amenable number.

21494551856 is a deficient number, since it is larger than the sum of its proper divisors (20256055696).

21494551856 is a wasteful number, since it uses less digits than its factorization.

21494551856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3384308 (or 3384302 counting only the distinct ones).

The product of its digits is 1728000, while the sum is 50.

The spelling of 21494551856 in words is "twenty-one billion, four hundred ninety-four million, five hundred fifty-one thousand, eight hundred fifty-six".