81078061 has 2 divisors, whose sum is σ = 81078062. Its totient is φ = 81078060.

The previous prime is 81078043. The next prime is 81078071. The reversal of 81078061 is 16087018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44475561 + 36602500 = 6669^2 + 6050^2 .

It is a cyclic number.

It is not a de Polignac number, because 81078061 - 2⁵ = 81078029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81078001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40539030 + 40539031.

It is an arithmetic number, because the mean of its divisors is an integer number (40539031).

Almost surely, 2^81078061 is an apocalyptic number.

It is an amenable number.

81078061 is a deficient number, since it is larger than the sum of its proper divisors (1).

81078061 is an equidigital number, since it uses as much as digits as its factorization.

81078061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2688, while the sum is 31.

The square root of 81078061 is about 9004.3356778832. The cubic root of 81078061 is about 432.8138183723.

The spelling of 81078061 in words is "eighty-one million, seventy-eight thousand, sixty-one".