78221 has 8 divisors (see below), whose sum is σ = 92064. Its totient is φ = 65520.

The previous prime is 78203. The next prime is 78229. The reversal of 78221 is 12287.

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

It is not a de Polignac number, because 78221 - 2⁶ = 78157 is a prime.

It is a super-2 number, since 2×78221² = 12237049682, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78193 and 78202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78229) 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, 131 + ... + 416.

It is an arithmetic number, because the mean of its divisors is an integer number (11508).

2⁷⁸²²¹ is an apocalyptic number.

It is an amenable number.

78221 is a deficient number, since it is larger than the sum of its proper divisors (13843).

78221 is a wasteful number, since it uses less digits than its factorization.

78221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571.

The product of its digits is 224, while the sum is 20.

The square root of 78221 is about 279.6801744851. The cubic root of 78221 is about 42.7669016533.

It can be divided in two parts, 7 and 8221, that added together give a palindrome (8228).

The spelling of 78221 in words is "seventy-eight thousand, two hundred twenty-one".