21856900557387 has 16 divisors (see below), whose sum is σ = 33323218290432. Its totient is φ = 12483108063840.

The previous prime is 21856900557361. The next prime is 21856900557397. The reversal of 21856900557387 is 78375500965812.

It is not a de Polignac number, because 21856900557387 - 2¹² = 21856900553291 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21856900557307) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 272850564 + ... + 272930657.

It is an arithmetic number, because the mean of its divisors is an integer number (2082701143152).

Almost surely, 2^{21856900557387} is an apocalyptic number.

21856900557387 is a deficient number, since it is larger than the sum of its proper divisors (11466317733045).

21856900557387 is a wasteful number, since it uses less digits than its factorization.

21856900557387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 545783138.

The product of its (nonzero) digits is 127008000, while the sum is 66.

The spelling of 21856900557387 in words is "twenty-one trillion, eight hundred fifty-six billion, nine hundred million, five hundred fifty-seven thousand, three hundred eighty-seven".