78858221 has 8 divisors (see below), whose sum is σ = 87853080. Its totient is φ = 70281792.

The previous prime is 78858193. The next prime is 78858229. The reversal of 78858221 is 12285887.

It can be written as a sum of positive squares in 4 ways, for example, as 22458121 + 56400100 = 4739^2 + 7510^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78858221 - 2¹⁴ = 78841837 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78858229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 104210 + ... + 104963.

It is an arithmetic number, because the mean of its divisors is an integer number (10981635).

Almost surely, 2^78858221 is an apocalyptic number.

It is an amenable number.

78858221 is a deficient number, since it is larger than the sum of its proper divisors (8994859).

78858221 is a wasteful number, since it uses less digits than its factorization.

78858221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209215.

The product of its digits is 71680, while the sum is 41.

The square root of 78858221 is about 8880.2151437902. The cubic root of 78858221 is about 428.8272007793.

The spelling of 78858221 in words is "seventy-eight million, eight hundred fifty-eight thousand, two hundred twenty-one".