51604561 has 2 divisors, whose sum is σ = 51604562. Its totient is φ = 51604560.

The previous prime is 51604549. The next prime is 51604573. The reversal of 51604561 is 16540615.

It is a balanced prime because it is at equal distance from previous prime (51604549) and next prime (51604573).

It can be written as a sum of positive squares in only one way, i.e., 51051025 + 553536 = 7145^2 + 744^2 .

It is a cyclic number.

It is not a de Polignac number, because 51604561 - 2¹⁹ = 51080273 is a prime.

It is not a weakly prime, because it can be changed into another prime (51604661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25802280 + 25802281.

It is an arithmetic number, because the mean of its divisors is an integer number (25802281).

Almost surely, 2^51604561 is an apocalyptic number.

It is an amenable number.

51604561 is a deficient number, since it is larger than the sum of its proper divisors (1).

51604561 is an equidigital number, since it uses as much as digits as its factorization.

51604561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 51604561 is about 7183.6314632642. The cubic root of 51604561 is about 372.3025658238.

The spelling of 51604561 in words is "fifty-one million, six hundred four thousand, five hundred sixty-one".