21848938581 has 32 divisors (see below), whose sum is σ = 30371806080. Its totient is φ = 13959244800.

The previous prime is 21848938549. The next prime is 21848938589. The reversal of 21848938581 is 18583984812.

It is not a de Polignac number, because 21848938581 - 2⁵ = 21848938549 is a prime.

It is a super-2 number, since 2×21848938581² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21848938589) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7749190 + ... + 7752008.

It is an arithmetic number, because the mean of its divisors is an integer number (949118940).

Almost surely, 2^21848938581 is an apocalyptic number.

It is an amenable number.

21848938581 is a deficient number, since it is larger than the sum of its proper divisors (8522867499).

21848938581 is a wasteful number, since it uses less digits than its factorization.

21848938581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3957.

The product of its digits is 4423680, while the sum is 57.

The spelling of 21848938581 in words is "twenty-one billion, eight hundred forty-eight million, nine hundred thirty-eight thousand, five hundred eighty-one".