84162721 has 2 divisors, whose sum is σ = 84162722. Its totient is φ = 84162720.

The previous prime is 84162707. The next prime is 84162763. The reversal of 84162721 is 12726148.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72846225 + 11316496 = 8535^2 + 3364^2 .

It is a cyclic number.

It is not a de Polignac number, because 84162721 - 2¹⁹ = 83638433 is a prime.

It is a super-2 number, since 2×84162721² = 14166727212247682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (84162521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42081360 + 42081361.

It is an arithmetic number, because the mean of its divisors is an integer number (42081361).

Almost surely, 2^84162721 is an apocalyptic number.

It is an amenable number.

84162721 is a deficient number, since it is larger than the sum of its proper divisors (1).

84162721 is an equidigital number, since it uses as much as digits as its factorization.

84162721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5376, while the sum is 31.

The square root of 84162721 is about 9174.0242532926. The cubic root of 84162721 is about 438.2345251253.

Adding to 84162721 its reverse (12726148), we get a palindrome (96888869).

The spelling of 84162721 in words is "eighty-four million, one hundred sixty-two thousand, seven hundred twenty-one".