78244538 has 4 divisors (see below), whose sum is σ = 117366810. Its totient is φ = 39122268.

The previous prime is 78244513. The next prime is 78244541. The reversal of 78244538 is 83544287.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83544287 = 31 ⋅2694977.

It can be written as a sum of positive squares in only one way, i.e., 65334889 + 12909649 = 8083^2 + 3593^2 .

It is a super-2 number, since 2×78244538² = 12244415453666888, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 78244495 and 78244504.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19561133 + ... + 19561136.

Almost surely, 2^78244538 is an apocalyptic number.

78244538 is a deficient number, since it is larger than the sum of its proper divisors (39122272).

78244538 is a wasteful number, since it uses less digits than its factorization.

78244538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39122271.

The product of its digits is 215040, while the sum is 41.

The square root of 78244538 is about 8845.5942705960. The cubic root of 78244538 is about 427.7119098049.

The spelling of 78244538 in words is "seventy-eight million, two hundred forty-four thousand, five hundred thirty-eight".