78387949 has 2 divisors, whose sum is σ = 78387950. Its totient is φ = 78387948.

The previous prime is 78387929. The next prime is 78387971. The reversal of 78387949 is 94978387.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71402500 + 6985449 = 8450^2 + 2643^2 .

It is a cyclic number.

It is not a de Polignac number, because 78387949 - 2⁵ = 78387917 is a prime.

It is a super-2 number, since 2×78387949² = 12289341096853202, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78387949.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78387919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39193974 + 39193975.

It is an arithmetic number, because the mean of its divisors is an integer number (39193975).

Almost surely, 2^78387949 is an apocalyptic number.

It is an amenable number.

78387949 is a deficient number, since it is larger than the sum of its proper divisors (1).

78387949 is an equidigital number, since it uses as much as digits as its factorization.

78387949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3048192, while the sum is 55.

The square root of 78387949 is about 8853.6969114602. The cubic root of 78387949 is about 427.9730618181.

The spelling of 78387949 in words is "seventy-eight million, three hundred eighty-seven thousand, nine hundred forty-nine".