77640001 has 2 divisors, whose sum is σ = 77640002. Its totient is φ = 77640000.

The previous prime is 77639999. The next prime is 77640041. The reversal of 77640001 is 10004677.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39187600 + 38452401 = 6260^2 + 6201^2 .

It is a cyclic number.

It is not a de Polignac number, because 77640001 - 2¹ = 77639999 is a prime.

Together with 77639999, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (77640041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38820000 + 38820001.

It is an arithmetic number, because the mean of its divisors is an integer number (38820001).

Almost surely, 2^77640001 is an apocalyptic number.

It is an amenable number.

77640001 is a deficient number, since it is larger than the sum of its proper divisors (1).

77640001 is an equidigital number, since it uses as much as digits as its factorization.

77640001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1176, while the sum is 25.

The square root of 77640001 is about 8811.3563655092. The cubic root of 77640001 is about 426.6075240153.

Adding to 77640001 its reverse (10004677), we get a palindrome (87644678).

The spelling of 77640001 in words is "seventy-seven million, six hundred forty thousand, one".