78990061 has 2 divisors, whose sum is σ = 78990062. Its totient is φ = 78990060.

The previous prime is 78990053. The next prime is 78990071. The reversal of 78990061 is 16009987.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39614436 + 39375625 = 6294^2 + 6275^2 .

It is a cyclic number.

It is not a de Polignac number, because 78990061 - 2³ = 78990053 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 78989996 and 78990023.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78990071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39495030 + 39495031.

It is an arithmetic number, because the mean of its divisors is an integer number (39495031).

Almost surely, 2^78990061 is an apocalyptic number.

It is an amenable number.

78990061 is a deficient number, since it is larger than the sum of its proper divisors (1).

78990061 is an equidigital number, since it uses as much as digits as its factorization.

78990061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27216, while the sum is 40.

The square root of 78990061 is about 8887.6352872966. The cubic root of 78990061 is about 429.0660475754.

The spelling of 78990061 in words is "seventy-eight million, nine hundred ninety thousand, sixty-one".