21638038895 has 8 divisors (see below), whose sum is σ = 28326160080. Its totient is φ = 15736755520.

The previous prime is 21638038883. The next prime is 21638038897. The reversal of 21638038895 is 59883083612.

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

It is not a de Polignac number, because 21638038895 - 2⁴ = 21638038879 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21638038897) 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, 196709390 + ... + 196709499.

It is an arithmetic number, because the mean of its divisors is an integer number (3540770010).

Almost surely, 2^21638038895 is an apocalyptic number.

21638038895 is a deficient number, since it is larger than the sum of its proper divisors (6688121185).

21638038895 is a wasteful number, since it uses less digits than its factorization.

21638038895 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393418905.

The product of its (nonzero) digits is 2488320, while the sum is 53.

The spelling of 21638038895 in words is "twenty-one billion, six hundred thirty-eight million, thirty-eight thousand, eight hundred ninety-five".