28072155638 has 32 divisors (see below), whose sum is σ = 44191236096. Its totient is φ = 13348909728.

The previous prime is 28072155637. The next prime is 28072155649. The reversal of 28072155638 is 83655127082.

It is a super-3 number, since 3×28072155638³ (a number of 32 digits) contains 333 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 28072155592 and 28072155601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28072155637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13098395 + ... + 13100537.

It is an arithmetic number, because the mean of its divisors is an integer number (1380976128).

Almost surely, 2^28072155638 is an apocalyptic number.

28072155638 is a deficient number, since it is larger than the sum of its proper divisors (16119080458).

28072155638 is a wasteful number, since it uses less digits than its factorization.

28072155638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3668.

The product of its (nonzero) digits is 806400, while the sum is 47.

The spelling of 28072155638 in words is "twenty-eight billion, seventy-two million, one hundred fifty-five thousand, six hundred thirty-eight".