28378881645 has 32 divisors (see below), whose sum is σ = 48014152704. Its totient is φ = 14289907200.

The previous prime is 28378881607. The next prime is 28378881653. The reversal of 28378881645 is 54618887382.

It is not a de Polignac number, because 28378881645 - 2¹¹ = 28378879597 is a prime.

It is a super-3 number, since 3×28378881645³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 725202 + ... + 763331.

It is an arithmetic number, because the mean of its divisors is an integer number (1500442272).

Almost surely, 2^28378881645 is an apocalyptic number.

It is an amenable number.

28378881645 is a deficient number, since it is larger than the sum of its proper divisors (19635271059).

28378881645 is a wasteful number, since it uses less digits than its factorization.

28378881645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1488613.

The product of its digits is 20643840, while the sum is 60.

The spelling of 28378881645 in words is "twenty-eight billion, three hundred seventy-eight million, eight hundred eighty-one thousand, six hundred forty-five".