21061636144 has 10 divisors (see below), whose sum is σ = 40806920060. Its totient is φ = 10530818064.

The previous prime is 21061636129. The next prime is 21061636157. The reversal of 21061636144 is 44163616012.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 658176114 + ... + 658176145.

It is an arithmetic number, because the mean of its divisors is an integer number (4080692006).

Almost surely, 2^21061636144 is an apocalyptic number.

It is an amenable number.

21061636144 is a deficient number, since it is larger than the sum of its proper divisors (19745283916).

21061636144 is a wasteful number, since it uses less digits than its factorization.

21061636144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1316352267 (or 1316352261 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 34.

The spelling of 21061636144 in words is "twenty-one billion, sixty-one million, six hundred thirty-six thousand, one hundred forty-four".