28178684440 has 16 divisors (see below), whose sum is σ = 63402040080. Its totient is φ = 11271473760.

The previous prime is 28178684431. The next prime is 28178684459. The reversal of 28178684440 is 4448687182.

It is a super-2 number, since 2×28178684440² (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 3 ways as a sum of consecutive naturals, for example, 352233516 + ... + 352233595.

It is an arithmetic number, because the mean of its divisors is an integer number (3962627505).

Almost surely, 2^28178684440 is an apocalyptic number.

28178684440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28178684440 is an abundant number, since it is smaller than the sum of its proper divisors (35223355640).

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

28178684440 is a wasteful number, since it uses less digits than its factorization.

28178684440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 704467122 (or 704467118 counting only the distinct ones).

The product of its (nonzero) digits is 2752512, while the sum is 52.

The spelling of 28178684440 in words is "twenty-eight billion, one hundred seventy-eight million, six hundred eighty-four thousand, four hundred forty".