78218201 has 4 divisors (see below), whose sum is σ = 80126004. Its totient is φ = 76310400.

The previous prime is 78218197. The next prime is 78218213. The reversal of 78218201 is 10281287.

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 18696976 + 59521225 = 4324^2 + 7715^2 .

It is a cyclic number.

It is not a de Polignac number, because 78218201 - 2² = 78218197 is a prime.

It is a super-2 number, since 2×78218201² = 12236173935352802, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78248201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 953840 + ... + 953921.

It is an arithmetic number, because the mean of its divisors is an integer number (20031501).

Almost surely, 2^78218201 is an apocalyptic number.

It is an amenable number.

78218201 is a deficient number, since it is larger than the sum of its proper divisors (1907803).

78218201 is a wasteful number, since it uses less digits than its factorization.

78218201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1907802.

The product of its (nonzero) digits is 1792, while the sum is 29.

The square root of 78218201 is about 8844.1054380870. The cubic root of 78218201 is about 427.6639153464.

Adding to 78218201 its reverse (10281287), we get a palindrome (88499488).

The spelling of 78218201 in words is "seventy-eight million, two hundred eighteen thousand, two hundred one".