21061895728 has 40 divisors (see below), whose sum is σ = 41077604000. Its totient is φ = 10461394944.

The previous prime is 21061895683. The next prime is 21061895741. The reversal of 21061895728 is 82759816012.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2137918 + ... + 2147746.

It is an arithmetic number, because the mean of its divisors is an integer number (1026940100).

Almost surely, 2^21061895728 is an apocalyptic number.

It is an amenable number.

21061895728 is a deficient number, since it is larger than the sum of its proper divisors (20015708272).

21061895728 is a wasteful number, since it uses less digits than its factorization.

21061895728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10709 (or 10703 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 49.

The spelling of 21061895728 in words is "twenty-one billion, sixty-one million, eight hundred ninety-five thousand, seven hundred twenty-eight".