84401521 has 2 divisors, whose sum is σ = 84401522. Its totient is φ = 84401520.

The previous prime is 84401509. The next prime is 84401539. The reversal of 84401521 is 12510448.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74390625 + 10010896 = 8625^2 + 3164^2 .

It is a cyclic number.

It is not a de Polignac number, because 84401521 - 2¹⁷ = 84270449 is a prime.

It is a super-2 number, since 2×84401521² = 14247233494226882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (84401501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42200760 + 42200761.

It is an arithmetic number, because the mean of its divisors is an integer number (42200761).

Almost surely, 2^84401521 is an apocalyptic number.

It is an amenable number.

84401521 is a deficient number, since it is larger than the sum of its proper divisors (1).

84401521 is an equidigital number, since it uses as much as digits as its factorization.

84401521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1280, while the sum is 25.

The square root of 84401521 is about 9187.0300424022. The cubic root of 84401521 is about 438.6486102139.

Adding to 84401521 its reverse (12510448), we get a palindrome (96911969).

The spelling of 84401521 in words is "eighty-four million, four hundred one thousand, five hundred twenty-one".