84009681 has 24 divisors (see below), whose sum is σ = 140250240. Its totient is φ = 47462976.

The previous prime is 84009677. The next prime is 84009691. The reversal of 84009681 is 18690048.

It is a happy number.

It is not a de Polignac number, because 84009681 - 2² = 84009677 is a prime.

It is a super-2 number, since 2×84009681² = 14115253003443522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84009691) 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 23 ways as a sum of consecutive naturals, for example, 1885 + ... + 13098.

It is an arithmetic number, because the mean of its divisors is an integer number (5843760).

Almost surely, 2^84009681 is an apocalyptic number.

It is an amenable number.

84009681 is a deficient number, since it is larger than the sum of its proper divisors (56240559).

84009681 is a wasteful number, since it uses less digits than its factorization.

84009681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15085 (or 15082 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 84009681 is about 9165.6795165443. The cubic root of 84009681 is about 437.9687379952.

It can be divided in two parts, 8400 and 9681, that added together give a palindrome (18081).

The spelling of 84009681 in words is "eighty-four million, nine thousand, six hundred eighty-one".