84508781 has 6 divisors (see below), whose sum is σ = 98306190. Its totient is φ = 72436056.

The previous prime is 84508763. The next prime is 84508829. The reversal of 84508781 is 18780548.

It can be written as a sum of positive squares in only one way, i.e., 66275881 + 18232900 = 8141^2 + 4270^2 .

It is not a de Polignac number, because 84508781 - 2¹⁸ = 84246637 is a prime.

It is a super-2 number, since 2×84508781² = 14283468132211922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84508741) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 862286 + ... + 862383.

It is an arithmetic number, because the mean of its divisors is an integer number (16384365).

Almost surely, 2^84508781 is an apocalyptic number.

It is an amenable number.

84508781 is a deficient number, since it is larger than the sum of its proper divisors (13797409).

84508781 is a wasteful number, since it uses less digits than its factorization.

84508781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1724683 (or 1724676 counting only the distinct ones).

The product of its (nonzero) digits is 71680, while the sum is 41.

The square root of 84508781 is about 9192.8657664517. The cubic root of 84508781 is about 438.8343475198.

The spelling of 84508781 in words is "eighty-four million, five hundred eight thousand, seven hundred eighty-one".