1664404051 has 4 divisors (see below), whose sum is σ = 1664555400. Its totient is φ = 1664252704.

The previous prime is 1664404037. The next prime is 1664404069. The reversal of 1664404051 is 1504044661.

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 1664404051 - 2⁵ = 1664404019 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1664404031) 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, 57766 + ... + 81643.

It is an arithmetic number, because the mean of its divisors is an integer number (416138850).

Almost surely, 2^1664404051 is an apocalyptic number.

1664404051 is a deficient number, since it is larger than the sum of its proper divisors (151349).

1664404051 is a wasteful number, since it uses less digits than its factorization.

1664404051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151348.

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 1664404051 is about 40797.1083656673. The cubic root of 1664404051 is about 1185.0943330222.

The spelling of 1664404051 in words is "one billion, six hundred sixty-four million, four hundred four thousand, fifty-one".