74378639 has 2 divisors, whose sum is σ = 74378640. Its totient is φ = 74378638.

The previous prime is 74378611. The next prime is 74378653. The reversal of 74378639 is 93687347.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-74378639 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 74378593 and 74378602.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (74378609) 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, 37189319 + 37189320.

It is an arithmetic number, because the mean of its divisors is an integer number (37189320).

Almost surely, 2^74378639 is an apocalyptic number.

74378639 is a deficient number, since it is larger than the sum of its proper divisors (1).

74378639 is an equidigital number, since it uses as much as digits as its factorization.

74378639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 762048, while the sum is 47.

The square root of 74378639 is about 8624.3051314294. The cubic root of 74378639 is about 420.5484878646.

The spelling of 74378639 in words is "seventy-four million, three hundred seventy-eight thousand, six hundred thirty-nine".