78215369 has 2 divisors, whose sum is σ = 78215370. Its totient is φ = 78215368.

The previous prime is 78215353. The next prime is 78215393. The reversal of 78215369 is 96351287.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58323769 + 19891600 = 7637^2 + 4460^2 .

It is a cyclic number.

It is not a de Polignac number, because 78215369 - 2⁴ = 78215353 is a prime.

It is a super-2 number, since 2×78215369² = 12235287895612322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78215329) 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, 39107684 + 39107685.

It is an arithmetic number, because the mean of its divisors is an integer number (39107685).

Almost surely, 2^78215369 is an apocalyptic number.

It is an amenable number.

78215369 is a deficient number, since it is larger than the sum of its proper divisors (1).

78215369 is an equidigital number, since it uses as much as digits as its factorization.

78215369 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 41.

The square root of 78215369 is about 8843.9453299984. The cubic root of 78215369 is about 427.6587538929.

The spelling of 78215369 in words is "seventy-eight million, two hundred fifteen thousand, three hundred sixty-nine".