87781920 has 96 divisors (see below), whose sum is σ = 283010112. Its totient is φ = 22858752.

The previous prime is 87781909. The next prime is 87781937. The reversal of 87781920 is 2918778.

It is a tau number, because it is divible by the number of its divisors (96).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18514 + ... + 22766.

It is an arithmetic number, because the mean of its divisors is an integer number (2948022).

Almost surely, 2^87781920 is an apocalyptic number.

87781920 is a gapful number since it is divisible by the number (80) 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 87781920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141505056).

87781920 is an abundant number, since it is smaller than the sum of its proper divisors (195228192).

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

87781920 is a wasteful number, since it uses less digits than its factorization.

87781920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4314 (or 4306 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 42.

The square root of 87781920 is about 9369.2006062417. The cubic root of 87781920 is about 444.4282857088.

The spelling of 87781920 in words is "eighty-seven million, seven hundred eighty-one thousand, nine hundred twenty".