21638086943 has 8 divisors (see below), whose sum is σ = 23634812880. Its totient is φ = 19646298880.

The previous prime is 21638086879. The next prime is 21638087071. The reversal of 21638086943 is 34968083612.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21638086943 - 2⁶ = 21638086879 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21638086891 and 21638086900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21638086243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1225298 + ... + 1242831.

It is an arithmetic number, because the mean of its divisors is an integer number (2954351610).

Almost surely, 2^21638086943 is an apocalyptic number.

21638086943 is a deficient number, since it is larger than the sum of its proper divisors (1996725937).

21638086943 is a wasteful number, since it uses less digits than its factorization.

21638086943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2468937.

The product of its (nonzero) digits is 1492992, while the sum is 50.

The spelling of 21638086943 in words is "twenty-one billion, six hundred thirty-eight million, eighty-six thousand, nine hundred forty-three".