78397213 has 4 divisors (see below), whose sum is σ = 80220448. Its totient is φ = 76573980.

The previous prime is 78397201. The next prime is 78397219. The reversal of 78397213 is 31279387.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 78397213 - 2⁹ = 78396701 is a prime.

It is a super-2 number, since 2×78397213² = 12292246012334738, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78397219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 911553 + ... + 911638.

It is an arithmetic number, because the mean of its divisors is an integer number (20055112).

Almost surely, 2^78397213 is an apocalyptic number.

It is an amenable number.

78397213 is a deficient number, since it is larger than the sum of its proper divisors (1823235).

78397213 is a wasteful number, since it uses less digits than its factorization.

78397213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1823234.

The product of its digits is 63504, while the sum is 40.

The square root of 78397213 is about 8854.2200672899. The cubic root of 78397213 is about 427.9899206436.

The spelling of 78397213 in words is "seventy-eight million, three hundred ninety-seven thousand, two hundred thirteen".