66624739 has 2 divisors, whose sum is σ = 66624740. Its totient is φ = 66624738.

The previous prime is 66624737. The next prime is 66624787. The reversal of 66624739 is 93742666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66624739 - 2¹ = 66624737 is a prime.

Together with 66624737, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 66624695 and 66624704.

It is not a weakly prime, because it can be changed into another prime (66624731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33312369 + 33312370.

It is an arithmetic number, because the mean of its divisors is an integer number (33312370).

Almost surely, 2^66624739 is an apocalyptic number.

66624739 is a deficient number, since it is larger than the sum of its proper divisors (1).

66624739 is an equidigital number, since it uses as much as digits as its factorization.

66624739 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 43.

The square root of 66624739 is about 8162.3978707240. The cubic root of 66624739 is about 405.3951110326.

The spelling of 66624739 in words is "sixty-six million, six hundred twenty-four thousand, seven hundred thirty-nine".