51191421 has 8 divisors (see below), whose sum is σ = 68299104. Its totient is φ = 34105680.

The previous prime is 51191419. The next prime is 51191429. The reversal of 51191421 is 12419115.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51191421 - 2¹ = 51191419 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 51191391 and 51191400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51191429) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1086 + ... + 10176.

It is an arithmetic number, because the mean of its divisors is an integer number (8537388).

Almost surely, 2^51191421 is an apocalyptic number.

It is an amenable number.

51191421 is a deficient number, since it is larger than the sum of its proper divisors (17107683).

51191421 is a wasteful number, since it uses less digits than its factorization.

51191421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10971.

The product of its digits is 360, while the sum is 24.

The square root of 51191421 is about 7154.8180270360. The cubic root of 51191421 is about 371.3063658479.

The spelling of 51191421 in words is "fifty-one million, one hundred ninety-one thousand, four hundred twenty-one".