84639749 has 2 divisors, whose sum is σ = 84639750. Its totient is φ = 84639748.

The previous prime is 84639733. The next prime is 84639761. The reversal of 84639749 is 94793648.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84309124 + 330625 = 9182^2 + 575^2 .

It is a cyclic number.

It is not a de Polignac number, because 84639749 - 2⁴ = 84639733 is a prime.

It is a super-2 number, since 2×84639749² = 14327774221566002, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 84639697 and 84639706.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84639649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42319874 + 42319875.

It is an arithmetic number, because the mean of its divisors is an integer number (42319875).

Almost surely, 2^84639749 is an apocalyptic number.

It is an amenable number.

84639749 is a deficient number, since it is larger than the sum of its proper divisors (1).

84639749 is an equidigital number, since it uses as much as digits as its factorization.

84639749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1306368, while the sum is 50.

The square root of 84639749 is about 9199.9863586855. The cubic root of 84639749 is about 439.0609259173.

The spelling of 84639749 in words is "eighty-four million, six hundred thirty-nine thousand, seven hundred forty-nine".