1664507423 has 4 divisors (see below), whose sum is σ = 1664825448. Its totient is φ = 1664189400.

The previous prime is 1664507413. The next prime is 1664507437. The reversal of 1664507423 is 3247054661.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1664507423 - 2¹² = 1664503327 is a prime.

It is a super-2 number, since 2×1664507423² = 5541169922444201858, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664507413) 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, 151028 + ... + 161673.

It is an arithmetic number, because the mean of its divisors is an integer number (416206362).

Almost surely, 2^1664507423 is an apocalyptic number.

1664507423 is a deficient number, since it is larger than the sum of its proper divisors (318025).

1664507423 is an equidigital number, since it uses as much as digits as its factorization.

1664507423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318024.

The product of its (nonzero) digits is 120960, while the sum is 38.

The square root of 1664507423 is about 40798.3752495121. The cubic root of 1664507423 is about 1185.1188669357.

The spelling of 1664507423 in words is "one billion, six hundred sixty-four million, five hundred seven thousand, four hundred twenty-three".