28133682381 has 48 divisors (see below), whose sum is σ = 49194273024. Its totient is φ = 15124741632.

The previous prime is 28133682373. The next prime is 28133682403. The reversal of 28133682381 is 18328633182.

28133682381 is a `hidden beast` number, since 2 + 81 + 336 + 8 + 238 + 1 = 666.

It is not a de Polignac number, because 28133682381 - 2³ = 28133682373 is a prime.

It is a super-2 number, since 2×28133682381² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28133682331) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4680480 + ... + 4686486.

It is an arithmetic number, because the mean of its divisors is an integer number (1024880688).

Almost surely, 2^28133682381 is an apocalyptic number.

28133682381 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

28133682381 is a deficient number, since it is larger than the sum of its proper divisors (21060590643).

28133682381 is a wasteful number, since it uses less digits than its factorization.

28133682381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10410 (or 10407 counting only the distinct ones).

The product of its digits is 331776, while the sum is 45.

The spelling of 28133682381 in words is "twenty-eight billion, one hundred thirty-three million, six hundred eighty-two thousand, three hundred eighty-one".