21868616045 has 16 divisors (see below), whose sum is σ = 26540846640. Its totient is φ = 17296588800.

The previous prime is 21868616017. The next prime is 21868616069. The reversal of 21868616045 is 54061686812.

It can be written as a sum of positive squares in 8 ways, for example, as 2133423721 + 19735192324 = 46189^2 + 140482^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21868616045 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 207725 + ... + 294765.

It is an arithmetic number, because the mean of its divisors is an integer number (1658802915).

Almost surely, 2^21868616045 is an apocalyptic number.

It is an amenable number.

21868616045 is a deficient number, since it is larger than the sum of its proper divisors (4672230595).

21868616045 is a wasteful number, since it uses less digits than its factorization.

21868616045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87616.

The product of its (nonzero) digits is 552960, while the sum is 47.

The spelling of 21868616045 in words is "twenty-one billion, eight hundred sixty-eight million, six hundred sixteen thousand, forty-five".