1664426767 has 4 divisors (see below), whose sum is σ = 1664534880. Its totient is φ = 1664318656.

The previous prime is 1664426737. The next prime is 1664426779. The reversal of 1664426767 is 7676244661.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1664426767 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1664426767.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664426737) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26167 + ... + 63352.

It is an arithmetic number, because the mean of its divisors is an integer number (416133720).

Almost surely, 2^1664426767 is an apocalyptic number.

1664426767 is a deficient number, since it is larger than the sum of its proper divisors (108113).

1664426767 is an equidigital number, since it uses as much as digits as its factorization.

1664426767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108112.

The product of its digits is 2032128, while the sum is 49.

The square root of 1664426767 is about 40797.3867668016. The cubic root of 1664426767 is about 1185.0997244375.

The spelling of 1664426767 in words is "one billion, six hundred sixty-four million, four hundred twenty-six thousand, seven hundred sixty-seven".