51490561 has 4 divisors (see below), whose sum is σ = 51626800. Its totient is φ = 51354324.

The previous prime is 51490531. The next prime is 51490577. The reversal of 51490561 is 16509415.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51490561 - 2⁵ = 51490529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51490531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67551 + ... + 68308.

It is an arithmetic number, because the mean of its divisors is an integer number (12906700).

Almost surely, 2^51490561 is an apocalyptic number.

It is an amenable number.

51490561 is a deficient number, since it is larger than the sum of its proper divisors (136239).

51490561 is a wasteful number, since it uses less digits than its factorization.

51490561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136238.

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 51490561 is about 7175.6923707751. The cubic root of 51490561 is about 372.0282116231.

Adding to 51490561 its reverse (16509415), we get a palindrome (67999976).

The spelling of 51490561 in words is "fifty-one million, four hundred ninety thousand, five hundred sixty-one".