78121259 has 2 divisors, whose sum is σ = 78121260. Its totient is φ = 78121258.

The previous prime is 78121247. The next prime is 78121279. The reversal of 78121259 is 95212187.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78121259 - 2⁴ = 78121243 is a prime.

It is a super-2 number, since 2×78121259² = 12205862215490162, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78121279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39060629 + 39060630.

It is an arithmetic number, because the mean of its divisors is an integer number (39060630).

Almost surely, 2^78121259 is an apocalyptic number.

78121259 is a deficient number, since it is larger than the sum of its proper divisors (1).

78121259 is an equidigital number, since it uses as much as digits as its factorization.

78121259 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10080, while the sum is 35.

The square root of 78121259 is about 8838.6231393809. The cubic root of 78121259 is about 427.4871630722.

The spelling of 78121259 in words is "seventy-eight million, one hundred twenty-one thousand, two hundred fifty-nine".