51820961 has 4 divisors (see below), whose sum is σ = 54548400. Its totient is φ = 49093524.

The previous prime is 51820957. The next prime is 51820969. The reversal of 51820961 is 16902815.

51820961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 51820961 - 2² = 51820957 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51820969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1363691 + ... + 1363728.

It is an arithmetic number, because the mean of its divisors is an integer number (13637100).

Almost surely, 2^51820961 is an apocalyptic number.

It is an amenable number.

51820961 is a deficient number, since it is larger than the sum of its proper divisors (2727439).

51820961 is a wasteful number, since it uses less digits than its factorization.

51820961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2727438.

The product of its (nonzero) digits is 4320, while the sum is 32.

The square root of 51820961 is about 7198.6777258049. The cubic root of 51820961 is about 372.8222480575.

The spelling of 51820961 in words is "fifty-one million, eight hundred twenty thousand, nine hundred sixty-one".