80978749 has 2 divisors, whose sum is σ = 80978750. Its totient is φ = 80978748.

The previous prime is 80978743. The next prime is 80978767. The reversal of 80978749 is 94787908.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47858724 + 33120025 = 6918^2 + 5755^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-80978749 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 80978696 and 80978705.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (80978743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40489374 + 40489375.

It is an arithmetic number, because the mean of its divisors is an integer number (40489375).

Almost surely, 2^80978749 is an apocalyptic number.

It is an amenable number.

80978749 is a deficient number, since it is larger than the sum of its proper divisors (1).

80978749 is an equidigital number, since it uses as much as digits as its factorization.

80978749 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1016064, while the sum is 52.

The square root of 80978749 is about 8998.8193114430. The cubic root of 80978749 is about 432.6370292078.

The spelling of 80978749 in words is "eighty million, nine hundred seventy-eight thousand, seven hundred forty-nine".