78398737 has 2 divisors, whose sum is σ = 78398738. Its totient is φ = 78398736.

The previous prime is 78398717. The next prime is 78398741. The reversal of 78398737 is 73789387.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74494161 + 3904576 = 8631^2 + 1976^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78398737 is a prime.

It is a super-2 number, since 2×78398737² = 12292723926390338, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78398707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39199368 + 39199369.

It is an arithmetic number, because the mean of its divisors is an integer number (39199369).

Almost surely, 2^78398737 is an apocalyptic number.

It is an amenable number.

78398737 is a deficient number, since it is larger than the sum of its proper divisors (1).

78398737 is an equidigital number, since it uses as much as digits as its factorization.

78398737 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1778112, while the sum is 52.

The square root of 78398737 is about 8854.3061275291. The cubic root of 78398737 is about 427.9926939243.

The spelling of 78398737 in words is "seventy-eight million, three hundred ninety-eight thousand, seven hundred thirty-seven".