51761391 has 16 divisors (see below), whose sum is σ = 75437568. Its totient is φ = 31308800.

The previous prime is 51761383. The next prime is 51761401. The reversal of 51761391 is 19316715.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 51761391 - 2³ = 51761383 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51761321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19930 + ... + 22376.

It is an arithmetic number, because the mean of its divisors is an integer number (4714848).

Almost surely, 2^51761391 is an apocalyptic number.

51761391 is the 3846-th nonagonal number.

51761391 is a deficient number, since it is larger than the sum of its proper divisors (23676177).

51761391 is a wasteful number, since it uses less digits than its factorization.

51761391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3102.

The product of its digits is 5670, while the sum is 33.

The square root of 51761391 is about 7194.5389706360. The cubic root of 51761391 is about 372.6793358952.

The spelling of 51761391 in words is "fifty-one million, seven hundred sixty-one thousand, three hundred ninety-one".