87778890 has 56 divisors (see below), whose sum is σ = 236914308. Its totient is φ = 23405760.

The previous prime is 87778849. The next prime is 87778897. The reversal of 87778890 is 9887778.

It can be written as a sum of positive squares in 2 ways, for example, as 87778161 + 729 = 9369^2 + 27^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (87778897) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 1270 + ... + 13310.

Almost surely, 2^87778890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 87778890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118457154).

87778890 is an abundant number, since it is smaller than the sum of its proper divisors (149135418).

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

87778890 is a wasteful number, since it uses less digits than its factorization.

87778890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12066 (or 12051 counting only the distinct ones).

The product of its (nonzero) digits is 1580544, while the sum is 54.

The square root of 87778890 is about 9369.0389048184. The cubic root of 87778890 is about 444.4231721532.

The spelling of 87778890 in words is "eighty-seven million, seven hundred seventy-eight thousand, eight hundred ninety".