21156361870 has 64 divisors (see below), whose sum is σ = 45838425600. Its totient is φ = 6867918720.

The previous prime is 21156361801. The next prime is 21156361901. The reversal of 21156361870 is 7816365112.

It is a happy number.

21156361870 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3150076 + ... + 3156784.

It is an arithmetic number, because the mean of its divisors is an integer number (716225400).

Almost surely, 2^21156361870 is an apocalyptic number.

21156361870 is an abundant number, since it is smaller than the sum of its proper divisors (24682063730).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21156361870 is a wasteful number, since it uses less digits than its factorization.

21156361870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9113.

The product of its (nonzero) digits is 60480, while the sum is 40.

The spelling of 21156361870 in words is "twenty-one billion, one hundred fifty-six million, three hundred sixty-one thousand, eight hundred seventy".