78356261 has 2 divisors, whose sum is σ = 78356262. Its totient is φ = 78356260.

The previous prime is 78356237. The next prime is 78356273. The reversal of 78356261 is 16265387.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75777025 + 2579236 = 8705^2 + 1606^2 .

It is a cyclic number.

It is not a de Polignac number, because 78356261 - 2¹⁸ = 78094117 is a prime.

It is a super-2 number, since 2×78356261² = 12279407275800242, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78356221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39178130 + 39178131.

It is an arithmetic number, because the mean of its divisors is an integer number (39178131).

Almost surely, 2^78356261 is an apocalyptic number.

It is an amenable number.

78356261 is a deficient number, since it is larger than the sum of its proper divisors (1).

78356261 is an equidigital number, since it uses as much as digits as its factorization.

78356261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 38.

The square root of 78356261 is about 8851.9071956274. The cubic root of 78356261 is about 427.9153852731.

The spelling of 78356261 in words is "seventy-eight million, three hundred fifty-six thousand, two hundred sixty-one".