8461639 has 2 divisors, whose sum is σ = 8461640. Its totient is φ = 8461638.

The previous prime is 8461637. The next prime is 8461643. The reversal of 8461639 is 9361648.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 8461639 - 2¹ = 8461637 is a prime.

Together with 8461637, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 8461598 and 8461607.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8461633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4230819 + 4230820.

It is an arithmetic number, because the mean of its divisors is an integer number (4230820).

Almost surely, 2^8461639 is an apocalyptic number.

8461639 is a deficient number, since it is larger than the sum of its proper divisors (1).

8461639 is an equidigital number, since it uses as much as digits as its factorization.

8461639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 37.

The square root of 8461639 is about 2908.8896507087. The cubic root of 8461639 is about 203.7752795864.

Subtracting 8461639 from its reverse (9361648), we obtain a palindrome (900009).

It can be divided in two parts, 846 and 1639, that added together give a triangular number (2485 = T₇₀).

The spelling of 8461639 in words is "eight million, four hundred sixty-one thousand, six hundred thirty-nine".