77938639 has 2 divisors, whose sum is σ = 77938640. Its totient is φ = 77938638.

The previous prime is 77938633. The next prime is 77938667. The reversal of 77938639 is 93683977.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 77938639 - 2⁹ = 77938127 is a prime.

It is a super-3 number, since 3×77938639³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77938633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38969319 + 38969320.

It is an arithmetic number, because the mean of its divisors is an integer number (38969320).

Almost surely, 2^77938639 is an apocalyptic number.

77938639 is a deficient number, since it is larger than the sum of its proper divisors (1).

77938639 is an equidigital number, since it uses as much as digits as its factorization.

77938639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1714608, while the sum is 52.

The square root of 77938639 is about 8828.2863002963. The cubic root of 77938639 is about 427.1537983456.

The spelling of 77938639 in words is "seventy-seven million, nine hundred thirty-eight thousand, six hundred thirty-nine".