51242391 has 12 divisors (see below), whose sum is σ = 76569480. Its totient is φ = 32983440.

The previous prime is 51242371. The next prime is 51242419. The reversal of 51242391 is 19324215.

It is not a de Polignac number, because 51242391 - 2¹⁵ = 51209623 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51242311) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 97905 + ... + 98426.

It is an arithmetic number, because the mean of its divisors is an integer number (6380790).

Almost surely, 2^51242391 is an apocalyptic number.

51242391 is a deficient number, since it is larger than the sum of its proper divisors (25327089).

51242391 is a wasteful number, since it uses less digits than its factorization.

51242391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196366 (or 196363 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 51242391 is about 7158.3790762993. The cubic root of 51242391 is about 371.4295584152.

The spelling of 51242391 in words is "fifty-one million, two hundred forty-two thousand, three hundred ninety-one".