1664564143 has 4 divisors (see below), whose sum is σ = 1815888168. Its totient is φ = 1513240120.

The previous prime is 1664564137. The next prime is 1664564149. The reversal of 1664564143 is 3414654661.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (1664564137) and next prime (1664564149).

It is a cyclic number.

It is not a de Polignac number, because 1664564143 - 2¹³ = 1664555951 is a prime.

It is a super-2 number, since 2×1664564143² = 5541547572322648898, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1664564096 and 1664564105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664564149) 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, 75661996 + ... + 75662017.

It is an arithmetic number, because the mean of its divisors is an integer number (453972042).

Almost surely, 2^1664564143 is an apocalyptic number.

1664564143 is a deficient number, since it is larger than the sum of its proper divisors (151324025).

1664564143 is a wasteful number, since it uses less digits than its factorization.

1664564143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151324024.

The product of its digits is 207360, while the sum is 40.

The square root of 1664564143 is about 40799.0703693111. The cubic root of 1664564143 is about 1185.1323282112.

The spelling of 1664564143 in words is "one billion, six hundred sixty-four million, five hundred sixty-four thousand, one hundred forty-three".