21838126165 has 16 divisors (see below), whose sum is σ = 26446469760. Its totient is φ = 17310646080.

The previous prime is 21838126153. The next prime is 21838126187. The reversal of 21838126165 is 56162183812.

It is not a de Polignac number, because 21838126165 - 2²⁹ = 21301255253 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 243070 + ... + 320560.

It is an arithmetic number, because the mean of its divisors is an integer number (1652904360).

Almost surely, 2^21838126165 is an apocalyptic number.

It is an amenable number.

21838126165 is a deficient number, since it is larger than the sum of its proper divisors (4608343595).

21838126165 is a wasteful number, since it uses less digits than its factorization.

21838126165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78012.

The product of its digits is 138240, while the sum is 43.

The spelling of 21838126165 in words is "twenty-one billion, eight hundred thirty-eight million, one hundred twenty-six thousand, one hundred sixty-five".