72878213 has 2 divisors, whose sum is σ = 72878214. Its totient is φ = 72878212.

The previous prime is 72878207. The next prime is 72878227. The reversal of 72878213 is 31287827.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72471169 + 407044 = 8513^2 + 638^2 .

It is an emirp because it is prime and its reverse (31287827) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72878213 - 2¹² = 72874117 is a prime.

It is a super-2 number, since 2×72878213² = 10622467860146738, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72878203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36439106 + 36439107.

It is an arithmetic number, because the mean of its divisors is an integer number (36439107).

Almost surely, 2^72878213 is an apocalyptic number.

It is an amenable number.

72878213 is a deficient number, since it is larger than the sum of its proper divisors (1).

72878213 is an equidigital number, since it uses as much as digits as its factorization.

72878213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 37632, while the sum is 38.

The square root of 72878213 is about 8536.8737251994. The cubic root of 72878213 is about 417.7013751190.

The spelling of 72878213 in words is "seventy-two million, eight hundred seventy-eight thousand, two hundred thirteen".