1664205051 has 4 divisors (see below), whose sum is σ = 2218940072. Its totient is φ = 1109470032.

The previous prime is 1664205031. The next prime is 1664205077. The reversal of 1664205051 is 1505024661.

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

It is not a de Polignac number, because 1664205051 - 2⁵ = 1664205019 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1664205031) 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, 277367506 + ... + 277367511.

It is an arithmetic number, because the mean of its divisors is an integer number (554735018).

Almost surely, 2^1664205051 is an apocalyptic number.

1664205051 is a deficient number, since it is larger than the sum of its proper divisors (554735021).

1664205051 is an equidigital number, since it uses as much as digits as its factorization.

1664205051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 554735020.

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 1664205051 is about 40794.6693944197. The cubic root of 1664205051 is about 1185.0471002661.

The spelling of 1664205051 in words is "one billion, six hundred sixty-four million, two hundred five thousand, fifty-one".