28991933453778 has 16 divisors (see below), whose sum is σ = 58039998446496. Its totient is φ = 9654622561440.

The previous prime is 28991933453767. The next prime is 28991933453827. The reversal of 28991933453778 is 87735433919982.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2338807408 + ... + 2338819803.

It is an arithmetic number, because the mean of its divisors is an integer number (3627499902906).

Almost surely, 2^{28991933453778} is an apocalyptic number.

28991933453778 is an abundant number, since it is smaller than the sum of its proper divisors (29048064992718).

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

28991933453778 is a wasteful number, since it uses less digits than its factorization.

28991933453778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4677628249.

The product of its digits is 2469035520, while the sum is 78.

The spelling of 28991933453778 in words is "twenty-eight trillion, nine hundred ninety-one billion, nine hundred thirty-three million, four hundred fifty-three thousand, seven hundred seventy-eight".