51378331 has 4 divisors (see below), whose sum is σ = 51770664. Its totient is φ = 50986000.

The previous prime is 51378323. The next prime is 51378391. The reversal of 51378331 is 13387315.

It is a happy number.

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 51378331 - 2³ = 51378323 is a prime.

It is a super-2 number, since 2×51378331² = 5279465792691122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51378293 and 51378302.

It is not an unprimeable number, because it can be changed into a prime (51378391) 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, 195970 + ... + 196231.

It is an arithmetic number, because the mean of its divisors is an integer number (12942666).

Almost surely, 2^51378331 is an apocalyptic number.

51378331 is a deficient number, since it is larger than the sum of its proper divisors (392333).

51378331 is a wasteful number, since it uses less digits than its factorization.

51378331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 392332.

The product of its digits is 7560, while the sum is 31.

The square root of 51378331 is about 7167.8679535829. The cubic root of 51378331 is about 371.7577212832.

The spelling of 51378331 in words is "fifty-one million, three hundred seventy-eight thousand, three hundred thirty-one".