78242512252409 has 2 divisors, whose sum is σ = 78242512252410. Its totient is φ = 78242512252408.

The previous prime is 78242512252391. The next prime is 78242512252517. The reversal of 78242512252409 is 90425221524287.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42795408912400 + 35447103340009 = 6541820^2 + 5953747^2 .

It is a cyclic number.

It is not a de Polignac number, because 78242512252409 - 2³² = 78238217285113 is a prime.

It is a super-2 number, since 2×78242512252409² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78242512252109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39121256126204 + 39121256126205.

It is an arithmetic number, because the mean of its divisors is an integer number (39121256126205).

Almost surely, 2^{78242512252409} is an apocalyptic number.

It is an amenable number.

78242512252409 is a deficient number, since it is larger than the sum of its proper divisors (1).

78242512252409 is an equidigital number, since it uses as much as digits as its factorization.

78242512252409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6451200, while the sum is 53.

The spelling of 78242512252409 in words is "seventy-eight trillion, two hundred forty-two billion, five hundred twelve million, two hundred fifty-two thousand, four hundred nine".