21073831556 has 12 divisors (see below), whose sum is σ = 37148397468. Its totient is φ = 10460003712.

The previous prime is 21073831529. The next prime is 21073831609. The reversal of 21073831556 is 65513837012.

It can be written as a sum of positive squares in 2 ways, for example, as 13833523456 + 7240308100 = 117616^2 + 85090^2 .

It is a super-2 number, since 2×21073831556² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

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, 19227401 + ... + 19228496.

It is an arithmetic number, because the mean of its divisors is an integer number (3095699789).

Almost surely, 2^21073831556 is an apocalyptic number.

It is an amenable number.

21073831556 is a deficient number, since it is larger than the sum of its proper divisors (16074565912).

21073831556 is a wasteful number, since it uses less digits than its factorization.

21073831556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38456038 (or 38456036 counting only the distinct ones).

The product of its (nonzero) digits is 151200, while the sum is 41.

The spelling of 21073831556 in words is "twenty-one billion, seventy-three million, eight hundred thirty-one thousand, five hundred fifty-six".