84621681 has 24 divisors (see below), whose sum is σ = 126945000. Its totient is φ = 54254592.

The previous prime is 84621653. The next prime is 84621689. The reversal of 84621681 is 18612648.

It can be written as a sum of positive squares in 4 ways, for example, as 3459600 + 81162081 = 1860^2 + 9009^2 .

It is not a de Polignac number, because 84621681 - 2²² = 80427377 is a prime.

It is a super-2 number, since 2×84621681² = 14321657790531522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84621689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 90625 + ... + 91553.

It is an arithmetic number, because the mean of its divisors is an integer number (5289375).

Almost surely, 2^84621681 is an apocalyptic number.

It is an amenable number.

84621681 is a deficient number, since it is larger than the sum of its proper divisors (42323319).

84621681 is a wasteful number, since it uses less digits than its factorization.

84621681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1313 (or 1310 counting only the distinct ones).

The product of its digits is 18432, while the sum is 36.

The square root of 84621681 is about 9199.0043482977. The cubic root of 84621681 is about 439.0296816636.

The spelling of 84621681 in words is "eighty-four million, six hundred twenty-one thousand, six hundred eighty-one".