51191969 has 4 divisors (see below), whose sum is σ = 51208896. Its totient is φ = 51175044.

The previous prime is 51191963. The next prime is 51191971. The reversal of 51191969 is 96919115.

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, and also an emirpimes, since its reverse is a distinct semiprime: 96919115 = 5 ⋅19383823.

It is a cyclic number.

It is not a de Polignac number, because 51191969 - 2¹⁶ = 51126433 is a prime.

It is a super-2 number, since 2×51191969² = 5241235380193922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51191963) 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, 2549 + ... + 10434.

It is an arithmetic number, because the mean of its divisors is an integer number (12802224).

Almost surely, 2^51191969 is an apocalyptic number.

It is an amenable number.

51191969 is a deficient number, since it is larger than the sum of its proper divisors (16927).

51191969 is a wasteful number, since it uses less digits than its factorization.

51191969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16926.

The product of its digits is 21870, while the sum is 41.

The square root of 51191969 is about 7154.8563228062. The cubic root of 51191969 is about 371.3076907780.

The spelling of 51191969 in words is "fifty-one million, one hundred ninety-one thousand, nine hundred sixty-nine".