78070261 has 2 divisors, whose sum is σ = 78070262. Its totient is φ = 78070260.

The previous prime is 78070247. The next prime is 78070277. The reversal of 78070261 is 16207087.

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., 53567761 + 24502500 = 7319^2 + 4950^2 .

It is a cyclic number.

It is not a de Polignac number, because 78070261 - 2⁷ = 78070133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78070561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39035130 + 39035131.

It is an arithmetic number, because the mean of its divisors is an integer number (39035131).

Almost surely, 2^78070261 is an apocalyptic number.

It is an amenable number.

78070261 is a deficient number, since it is larger than the sum of its proper divisors (1).

78070261 is an equidigital number, since it uses as much as digits as its factorization.

78070261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4704, while the sum is 31.

The square root of 78070261 is about 8835.7377167954. The cubic root of 78070261 is about 427.3941208100.

The spelling of 78070261 in words is "seventy-eight million, seventy thousand, two hundred sixty-one".