21961942768 has 10 divisors (see below), whose sum is σ = 42551264144. Its totient is φ = 10980971376.

The previous prime is 21961942747. The next prime is 21961942799. The reversal of 21961942768 is 86724916912.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 686310696 + ... + 686310727.

Almost surely, 2^21961942768 is an apocalyptic number.

It is an amenable number.

21961942768 is a deficient number, since it is larger than the sum of its proper divisors (20589321376).

21961942768 is a wasteful number, since it uses less digits than its factorization.

21961942768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1372621431 (or 1372621425 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 55.

The spelling of 21961942768 in words is "twenty-one billion, nine hundred sixty-one million, nine hundred forty-two thousand, seven hundred sixty-eight".