1664540447 has 2 divisors, whose sum is σ = 1664540448. Its totient is φ = 1664540446.

The previous prime is 1664540407. The next prime is 1664540459. The reversal of 1664540447 is 7440454661.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1664540447 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1664540407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832270223 + 832270224.

It is an arithmetic number, because the mean of its divisors is an integer number (832270224).

Almost surely, 2^1664540447 is an apocalyptic number.

1664540447 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664540447 is an equidigital number, since it uses as much as digits as its factorization.

1664540447 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 322560, while the sum is 41.

The square root of 1664540447 is about 40798.7799695040. The cubic root of 1664540447 is about 1185.1267045110.

The spelling of 1664540447 in words is "one billion, six hundred sixty-four million, five hundred forty thousand, four hundred forty-seven".