28781772731700 has 144 divisors (see below), whose sum is σ = 85216671783936. Its totient is φ = 7496227670400.

The previous prime is 28781772731693. The next prime is 28781772731773. The reversal of 28781772731700 is 713727718782.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 278110965 + ... + 278214435.

It is an arithmetic number, because the mean of its divisors is an integer number (591782442944).

Almost surely, 2^{28781772731700} is an apocalyptic number.

28781772731700 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28781772731700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42608335891968).

28781772731700 is an abundant number, since it is smaller than the sum of its proper divisors (56434899052236).

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

28781772731700 is a wasteful number, since it uses less digits than its factorization.

28781772731700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125094 (or 125087 counting only the distinct ones).

The product of its (nonzero) digits is 12907776, while the sum is 60.

The spelling of 28781772731700 in words is "twenty-eight trillion, seven hundred eighty-one billion, seven hundred seventy-two million, seven hundred thirty-one thousand, seven hundred".