78121250 has 20 divisors (see below), whose sum is σ = 146432814. Its totient is φ = 31248000.

The previous prime is 78121247. The next prime is 78121259. The reversal of 78121250 is 5212187.

It can be written as a sum of positive squares in 5 ways, for example, as 134689 + 77986561 = 367^2 + 8831^2 .

It is a super-2 number, since 2×78121250² = 12205859403125000, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (78121259) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 29999 + ... + 32498.

Almost surely, 2^78121250 is an apocalyptic number.

78121250 is a deficient number, since it is larger than the sum of its proper divisors (68311564).

78121250 is an equidigital number, since it uses as much as digits as its factorization.

78121250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62519 (or 62504 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 78121250 is about 8838.6226302518. The cubic root of 78121250 is about 427.4871466559.

The spelling of 78121250 in words is "seventy-eight million, one hundred twenty-one thousand, two hundred fifty".