78205213 has 4 divisors (see below), whose sum is σ = 78637468. Its totient is φ = 77772960.

The previous prime is 78205201. The next prime is 78205271. The reversal of 78205213 is 31250287.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4897369 + 73307844 = 2213^2 + 8562^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78205213 is a prime.

It is a super-2 number, since 2×78205213² = 12232110680750738, 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 (78205913) 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, 215856 + ... + 216217.

It is an arithmetic number, because the mean of its divisors is an integer number (19659367).

Almost surely, 2^78205213 is an apocalyptic number.

It is an amenable number.

78205213 is a deficient number, since it is larger than the sum of its proper divisors (432255).

78205213 is a wasteful number, since it uses less digits than its factorization.

78205213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432254.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 78205213 is about 8843.3711332274. The cubic root of 78205213 is about 427.6402430795.

The spelling of 78205213 in words is "seventy-eight million, two hundred five thousand, two hundred thirteen".