78138426 has 32 divisors (see below), whose sum is σ = 167581440. Its totient is φ = 24201216.

The previous prime is 78138419. The next prime is 78138427. The reversal of 78138426 is 62483187.

It is a super-2 number, since 2×78138426² = 12211227235514952, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78138427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3210 + ... + 12906.

It is an arithmetic number, because the mean of its divisors is an integer number (5236920).

Almost surely, 2^78138426 is an apocalyptic number.

78138426 is an abundant number, since it is smaller than the sum of its proper divisors (89443014).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78138426 is a wasteful number, since it uses less digits than its factorization.

78138426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9798.

The product of its digits is 64512, while the sum is 39.

The square root of 78138426 is about 8839.5942214561. The cubic root of 78138426 is about 427.5184739460.

The spelling of 78138426 in words is "seventy-eight million, one hundred thirty-eight thousand, four hundred twenty-six".