84781840 has 80 divisors (see below), whose sum is σ = 231610176. Its totient is φ = 28454400.

The previous prime is 84781817. The next prime is 84781847. The reversal of 84781840 is 4818748.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 84781793 and 84781802.

It is not an unprimeable number, because it can be changed into a prime (84781847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7735 + ... + 15145.

Almost surely, 2^84781840 is an apocalyptic number.

84781840 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 84781840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115805088).

84781840 is an abundant number, since it is smaller than the sum of its proper divisors (146828336).

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

84781840 is a wasteful number, since it uses less digits than its factorization.

84781840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7448 (or 7442 counting only the distinct ones).

The product of its (nonzero) digits is 57344, while the sum is 40.

The square root of 84781840 is about 9207.7054687908. The cubic root of 84781840 is about 439.3064832284.

The spelling of 84781840 in words is "eighty-four million, seven hundred eighty-one thousand, eight hundred forty".