85744639 has 2 divisors, whose sum is σ = 85744640. Its totient is φ = 85744638.

The previous prime is 85744573. The next prime is 85744661. The reversal of 85744639 is 93644758.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 85744639 - 2¹³ = 85736447 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85744669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42872319 + 42872320.

It is an arithmetic number, because the mean of its divisors is an integer number (42872320).

Almost surely, 2^85744639 is an apocalyptic number.

85744639 is a deficient number, since it is larger than the sum of its proper divisors (1).

85744639 is an equidigital number, since it uses as much as digits as its factorization.

85744639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 725760, while the sum is 46.

The square root of 85744639 is about 9259.8401174102. The cubic root of 85744639 is about 440.9631775618.

The spelling of 85744639 in words is "eighty-five million, seven hundred forty-four thousand, six hundred thirty-nine".