78229901 has 2 divisors, whose sum is σ = 78229902. Its totient is φ = 78229900.

The previous prime is 78229891. The next prime is 78229909. The reversal of 78229901 is 10992287.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74407876 + 3822025 = 8626^2 + 1955^2 .

It is a cyclic number.

It is not a de Polignac number, because 78229901 - 2²⁶ = 11121037 is a prime.

It is a super-2 number, since 2×78229901² = 12239834820939602, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78229909) 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 as a sum of consecutive naturals, namely, 39114950 + 39114951.

It is an arithmetic number, because the mean of its divisors is an integer number (39114951).

Almost surely, 2^78229901 is an apocalyptic number.

78229901 is the 3956-th centered decagonal number.

It is an amenable number.

78229901 is a deficient number, since it is larger than the sum of its proper divisors (1).

78229901 is an equidigital number, since it uses as much as digits as its factorization.

78229901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 78229901 is about 8844.7668708678. The cubic root of 78229901 is about 427.6852378275.

The spelling of 78229901 in words is "seventy-eight million, two hundred twenty-nine thousand, nine hundred one".