664040051 has 4 divisors (see below), whose sum is σ = 664555704. Its totient is φ = 663524400.

The previous prime is 664040011. The next prime is 664040081. The reversal of 664040051 is 150040466.

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 664040051 - 2¹⁰ = 664039027 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 664040051.

It is not an unprimeable number, because it can be changed into a prime (664040011) 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, 255890 + ... + 258471.

It is an arithmetic number, because the mean of its divisors is an integer number (166138926).

Almost surely, 2^664040051 is an apocalyptic number.

664040051 is a deficient number, since it is larger than the sum of its proper divisors (515653).

664040051 is a wasteful number, since it uses less digits than its factorization.

664040051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 515652.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 664040051 is about 25768.9745818494. The cubic root of 664040051 is about 872.4316746303.

The spelling of 664040051 in words is "six hundred sixty-four million, forty thousand, fifty-one".