21415793668 has 12 divisors (see below), whose sum is σ = 37517472972. Its totient is φ = 10696515680.

The previous prime is 21415793591. The next prime is 21415793669. The reversal of 21415793668 is 86639751412.

It can be written as a sum of positive squares in 2 ways, for example, as 6911927044 + 14503866624 = 83138^2 + 120432^2 .

It is not an unprimeable number, because it can be changed into a prime (21415793669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2841055 + ... + 2848582.

It is an arithmetic number, because the mean of its divisors is an integer number (3126456081).

Almost surely, 2^21415793668 is an apocalyptic number.

It is an amenable number.

21415793668 is a deficient number, since it is larger than the sum of its proper divisors (16101679304).

21415793668 is a wasteful number, since it uses less digits than its factorization.

21415793668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5690582 (or 5690580 counting only the distinct ones).

The product of its digits is 2177280, while the sum is 52.

The spelling of 21415793668 in words is "twenty-one billion, four hundred fifteen million, seven hundred ninety-three thousand, six hundred sixty-eight".