84220639 has 2 divisors, whose sum is σ = 84220640. Its totient is φ = 84220638.

The previous prime is 84220627. The next prime is 84220649. The reversal of 84220639 is 93602248.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 84220639 - 2⁵ = 84220607 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84220649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42110319 + 42110320.

It is an arithmetic number, because the mean of its divisors is an integer number (42110320).

Almost surely, 2^84220639 is an apocalyptic number.

84220639 is a deficient number, since it is larger than the sum of its proper divisors (1).

84220639 is an equidigital number, since it uses as much as digits as its factorization.

84220639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 84220639 is about 9177.1803403878. The cubic root of 84220639 is about 438.3350282415.

The spelling of 84220639 in words is "eighty-four million, two hundred twenty thousand, six hundred thirty-nine".