51990851 has 4 divisors (see below), whose sum is σ = 56717304. Its totient is φ = 47264400.

The previous prime is 51990847. The next prime is 51990857. The reversal of 51990851 is 15809915.

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

It is a cyclic number.

It is not a de Polignac number, because 51990851 - 2² = 51990847 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51990857) 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, 2363210 + ... + 2363231.

It is an arithmetic number, because the mean of its divisors is an integer number (14179326).

Almost surely, 2^51990851 is an apocalyptic number.

51990851 is a deficient number, since it is larger than the sum of its proper divisors (4726453).

51990851 is a wasteful number, since it uses less digits than its factorization.

51990851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4726452.

The product of its (nonzero) digits is 16200, while the sum is 38.

The square root of 51990851 is about 7210.4681540105. The cubic root of 51990851 is about 373.2292241769.

The spelling of 51990851 in words is "fifty-one million, nine hundred ninety thousand, eight hundred fifty-one".