80644649 has 2 divisors, whose sum is σ = 80644650. Its totient is φ = 80644648.

The previous prime is 80644643. The next prime is 80644657. The reversal of 80644649 is 94644608.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62094400 + 18550249 = 7880^2 + 4307^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-80644649 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (80644643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40322324 + 40322325.

It is an arithmetic number, because the mean of its divisors is an integer number (40322325).

Almost surely, 2^80644649 is an apocalyptic number.

It is an amenable number.

80644649 is a deficient number, since it is larger than the sum of its proper divisors (1).

80644649 is an equidigital number, since it uses as much as digits as its factorization.

80644649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 165888, while the sum is 41.

The square root of 80644649 is about 8980.2365781754. The cubic root of 80644649 is about 432.0412215609.

Subtracting from 80644649 its sum of digits (41), we obtain a palindrome (80644608).

The spelling of 80644649 in words is "eighty million, six hundred forty-four thousand, six hundred forty-nine".