64642939 has 2 divisors, whose sum is σ = 64642940. Its totient is φ = 64642938.

The previous prime is 64642931. The next prime is 64642969. The reversal of 64642939 is 93924646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64642939 - 2³ = 64642931 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 64642895 and 64642904.

It is not a weakly prime, because it can be changed into another prime (64642931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32321469 + 32321470.

It is an arithmetic number, because the mean of its divisors is an integer number (32321470).

Almost surely, 2^64642939 is an apocalyptic number.

64642939 is a deficient number, since it is larger than the sum of its proper divisors (1).

64642939 is an equidigital number, since it uses as much as digits as its factorization.

64642939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 279936, while the sum is 43.

The square root of 64642939 is about 8040.0832707131. The cubic root of 64642939 is about 401.3349957590.

The spelling of 64642939 in words is "sixty-four million, six hundred forty-two thousand, nine hundred thirty-nine".