28108978940 has 48 divisors (see below), whose sum is σ = 68315520000. Its totient is φ = 9515368512.

The previous prime is 28108978903. The next prime is 28108978979. The reversal of 28108978940 is 4987980182.

It is a super-2 number, since 2×28108978940² (a number of 22 digits) contains 22 as substring.

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, 1259690 + ... + 1281809.

It is an arithmetic number, because the mean of its divisors is an integer number (1423240000).

Almost surely, 2^28108978940 is an apocalyptic number.

28108978940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28108978940 is an abundant number, since it is smaller than the sum of its proper divisors (40206541060).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28108978940 is a wasteful number, since it uses less digits than its factorization.

28108978940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2541594 (or 2541592 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 56.

The spelling of 28108978940 in words is "twenty-eight billion, one hundred eight million, nine hundred seventy-eight thousand, nine hundred forty".