28181919190900 has 36 divisors (see below), whose sum is σ = 61155004679020. Its totient is φ = 11272723430400.

The previous prime is 28181919190811. The next prime is 28181919190907. The reversal of 28181919190900 is 909191918182.

It can be written as a sum of positive squares in 6 ways, for example, as 64331220496 + 28117587970404 = 253636^2 + 5302602^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28181919190907) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39437986 + ... + 40146214.

Almost surely, 2^{28181919190900} is an apocalyptic number.

28181919190900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28181919190900 is an abundant number, since it is smaller than the sum of its proper divisors (32973085488120).

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

28181919190900 is a wasteful number, since it uses less digits than its factorization.

28181919190900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1106164 (or 1106157 counting only the distinct ones).

The product of its (nonzero) digits is 839808, while the sum is 58.

The spelling of 28181919190900 in words is "twenty-eight trillion, one hundred eighty-one billion, nine hundred nineteen million, one hundred ninety thousand, nine hundred".