78121826 has 16 divisors (see below), whose sum is σ = 119902200. Its totient is φ = 38164608.

The previous prime is 78121819. The next prime is 78121843. The reversal of 78121826 is 62812187.

It can be written as a sum of positive squares in 4 ways, for example, as 77457601 + 664225 = 8801^2 + 815^2 .

It is a super-2 number, since 2×78121826² = 12206039395148552, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13460 + ... + 18368.

Almost surely, 2^78121826 is an apocalyptic number.

78121826 is a deficient number, since it is larger than the sum of its proper divisors (41780374).

78121826 is a wasteful number, since it uses less digits than its factorization.

78121826 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5093.

The product of its digits is 10752, while the sum is 35.

The square root of 78121826 is about 8838.6552144543. The cubic root of 78121826 is about 427.4881972962.

The spelling of 78121826 in words is "seventy-eight million, one hundred twenty-one thousand, eight hundred twenty-six".