78178213 has 4 divisors (see below), whose sum is σ = 79345120. Its totient is φ = 77011308.

The previous prime is 78178201. The next prime is 78178237. The reversal of 78178213 is 31287187.

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 78178213 - 2¹³ = 78170021 is a prime.

It is a super-2 number, since 2×78178213² = 12223665975746738, 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 (78178253) 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, 583353 + ... + 583486.

It is an arithmetic number, because the mean of its divisors is an integer number (19836280).

Almost surely, 2^78178213 is an apocalyptic number.

It is an amenable number.

78178213 is a deficient number, since it is larger than the sum of its proper divisors (1166907).

78178213 is a wasteful number, since it uses less digits than its factorization.

78178213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1166906.

The product of its digits is 18816, while the sum is 37.

The square root of 78178213 is about 8841.8444342795. The cubic root of 78178213 is about 427.5910237877.

The spelling of 78178213 in words is "seventy-eight million, one hundred seventy-eight thousand, two hundred thirteen".