51704561 has 4 divisors (see below), whose sum is σ = 51804324. Its totient is φ = 51604800.

The previous prime is 51704551. The next prime is 51704563. The reversal of 51704561 is 16540715.

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

It can be written as a sum of positive squares in 2 ways, for example, as 39137536 + 12567025 = 6256^2 + 3545^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51704561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51704563) 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, 49100 + ... + 50141.

It is an arithmetic number, because the mean of its divisors is an integer number (12951081).

Almost surely, 2^51704561 is an apocalyptic number.

It is an amenable number.

51704561 is a deficient number, since it is larger than the sum of its proper divisors (99763).

51704561 is an equidigital number, since it uses as much as digits as its factorization.

51704561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99762.

The product of its (nonzero) digits is 4200, while the sum is 29.

The square root of 51704561 is about 7190.5883625751. The cubic root of 51704561 is about 372.5428949297.

The spelling of 51704561 in words is "fifty-one million, seven hundred four thousand, five hundred sixty-one".