21686379950 has 12 divisors (see below), whose sum is σ = 40336666800. Its totient is φ = 8674551960.

The previous prime is 21686379947. The next prime is 21686379973. The reversal of 21686379950 is 5997368612.

It is a happy number.

It is a hoax number, since the sum of its digits (56) coincides with the sum of the digits of its distinct prime factors.

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 5 ways as a sum of consecutive naturals, for example, 216863750 + ... + 216863849.

It is an arithmetic number, because the mean of its divisors is an integer number (3361388900).

Almost surely, 2^21686379950 is an apocalyptic number.

21686379950 is a deficient number, since it is larger than the sum of its proper divisors (18650286850).

21686379950 is a wasteful number, since it uses less digits than its factorization.

21686379950 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433727611 (or 433727606 counting only the distinct ones).

The product of its (nonzero) digits is 4898880, while the sum is 56.

The spelling of 21686379950 in words is "twenty-one billion, six hundred eighty-six million, three hundred seventy-nine thousand, nine hundred fifty".