1664540423 has 16 divisors (see below), whose sum is σ = 2104038720. Its totient is φ = 1281401856.

The previous prime is 1664540407. The next prime is 1664540447. The reversal of 1664540423 is 3240454661.

It is not a de Polignac number, because 1664540423 - 2⁴ = 1664540407 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664540473) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 243818 + ... + 250551.

It is an arithmetic number, because the mean of its divisors is an integer number (131502420).

Almost surely, 2^1664540423 is an apocalyptic number.

1664540423 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1664540423 is a deficient number, since it is larger than the sum of its proper divisors (439498297).

1664540423 is a wasteful number, since it uses less digits than its factorization.

1664540423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 494426.

The product of its (nonzero) digits is 69120, while the sum is 35.

The square root of 1664540423 is about 40798.7796753775. The cubic root of 1664540423 is about 1185.1266988151.

The spelling of 1664540423 in words is "one billion, six hundred sixty-four million, five hundred forty thousand, four hundred twenty-three".