78982121 has 2 divisors, whose sum is σ = 78982122. Its totient is φ = 78982120.

The previous prime is 78982117. The next prime is 78982159. The reversal of 78982121 is 12128987.

It is an a-pointer prime, because the next prime (78982159) can be obtained adding 78982121 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57229225 + 21752896 = 7565^2 + 4664^2 .

It is a cyclic number.

It is not a de Polignac number, because 78982121 - 2² = 78982117 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78982181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39491060 + 39491061.

It is an arithmetic number, because the mean of its divisors is an integer number (39491061).

Almost surely, 2^78982121 is an apocalyptic number.

It is an amenable number.

78982121 is a deficient number, since it is larger than the sum of its proper divisors (1).

78982121 is an equidigital number, since it uses as much as digits as its factorization.

78982121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16128, while the sum is 38.

The square root of 78982121 is about 8887.1885880744. The cubic root of 78982121 is about 429.0516706671.

The spelling of 78982121 in words is "seventy-eight million, nine hundred eighty-two thousand, one hundred twenty-one".