1664540407 has 2 divisors, whose sum is σ = 1664540408. Its totient is φ = 1664540406.

The previous prime is 1664540399. The next prime is 1664540447. The reversal of 1664540407 is 7040454661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1664540407 - 2³ = 1664540399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1664540447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832270203 + 832270204.

It is an arithmetic number, because the mean of its divisors is an integer number (832270204).

Almost surely, 2^1664540407 is an apocalyptic number.

1664540407 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664540407 is an equidigital number, since it uses as much as digits as its factorization.

1664540407 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 80640, while the sum is 37.

The square root of 1664540407 is about 40798.7794792933. The cubic root of 1664540407 is about 1185.1266950179.

The spelling of 1664540407 in words is "one billion, six hundred sixty-four million, five hundred forty thousand, four hundred seven".