78119221 has 2 divisors, whose sum is σ = 78119222. Its totient is φ = 78119220.

The previous prime is 78119219. The next prime is 78119231. The reversal of 78119221 is 12291187.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47748100 + 30371121 = 6910^2 + 5511^2 .

It is a cyclic number.

It is not a de Polignac number, because 78119221 - 2¹ = 78119219 is a prime.

It is a super-2 number, since 2×78119221² = 12205225379293682, which contains 22 as substring.

Together with 78119219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78119231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39059610 + 39059611.

It is an arithmetic number, because the mean of its divisors is an integer number (39059611).

Almost surely, 2^78119221 is an apocalyptic number.

It is an amenable number.

78119221 is a deficient number, since it is larger than the sum of its proper divisors (1).

78119221 is an equidigital number, since it uses as much as digits as its factorization.

78119221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 31.

The square root of 78119221 is about 8838.5078491791. The cubic root of 78119221 is about 427.4834456615.

It can be divided in two parts, 781 and 19221, that added together give a palindrome (20002).

The spelling of 78119221 in words is "seventy-eight million, one hundred nineteen thousand, two hundred twenty-one".