51664573 has 4 divisors (see below), whose sum is σ = 53446140. Its totient is φ = 49883008.

The previous prime is 51664567. The next prime is 51664577. The reversal of 51664573 is 37546615.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 37546615 = 5 ⋅7509323.

It can be written as a sum of positive squares in 2 ways, for example, as 39463524 + 12201049 = 6282^2 + 3493^2 .

It is a cyclic number.

It is not a de Polignac number, because 51664573 - 2⁹ = 51664061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51664577) 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, 890740 + ... + 890797.

It is an arithmetic number, because the mean of its divisors is an integer number (13361535).

Almost surely, 2^51664573 is an apocalyptic number.

It is an amenable number.

51664573 is a deficient number, since it is larger than the sum of its proper divisors (1781567).

51664573 is a wasteful number, since it uses less digits than its factorization.

51664573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1781566.

The product of its digits is 75600, while the sum is 37.

The square root of 51664573 is about 7187.8072456070. The cubic root of 51664573 is about 372.4468293400.

The spelling of 51664573 in words is "fifty-one million, six hundred sixty-four thousand, five hundred seventy-three".