84457621 has 2 divisors, whose sum is σ = 84457622. Its totient is φ = 84457620.

The previous prime is 84457613. The next prime is 84457627. The reversal of 84457621 is 12675448.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84456100 + 1521 = 9190^2 + 39^2 .

It is a cyclic number.

It is not a de Polignac number, because 84457621 - 2³ = 84457613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84457627) 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 as a sum of consecutive naturals, namely, 42228810 + 42228811.

It is an arithmetic number, because the mean of its divisors is an integer number (42228811).

Almost surely, 2^84457621 is an apocalyptic number.

It is an amenable number.

84457621 is a deficient number, since it is larger than the sum of its proper divisors (1).

84457621 is an equidigital number, since it uses as much as digits as its factorization.

84457621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 53760, while the sum is 37.

The square root of 84457621 is about 9190.0827526198. The cubic root of 84457621 is about 438.7457756700.

It can be divided in two parts, 84457 and 621, that added together give a triangular number (85078 = T₄₁₂).

The spelling of 84457621 in words is "eighty-four million, four hundred fifty-seven thousand, six hundred twenty-one".