84064623721 has 9 divisors (see below), whose sum is σ = 91032638679. Its totient is φ = 77594634936.

The previous prime is 84064623703. The next prime is 84064623733. The reversal of 84064623721 is 12732646048.

The square root of 84064623721 is 289939.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 12435595225 + 71629028496 = 111515^2 + 267636^2 .

It is not a de Polignac number, because 84064623721 - 2⁵ = 84064623689 is a prime.

It is a super-2 number, since 2×84064623721² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (84064623521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3758056 + ... + 3780358.

It is an arithmetic number, because the mean of its divisors is an integer number (10114737631).

Almost surely, 2^84064623721 is an apocalyptic number.

84064623721 is the 289939-th square number.

84064623721 is the 144970-th centered octagonal number.

It is an amenable number.

84064623721 is a deficient number, since it is larger than the sum of its proper divisors (6968014958).

84064623721 is an frugal number, since it uses more digits than its factorization.

84064623721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44632 (or 22316 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 43.

The spelling of 84064623721 in words is "eighty-four billion, sixty-four million, six hundred twenty-three thousand, seven hundred twenty-one".