51309031 has 2 divisors, whose sum is σ = 51309032. Its totient is φ = 51309030.

The previous prime is 51309029. The next prime is 51309059. The reversal of 51309031 is 13090315.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51309031 - 2¹ = 51309029 is a prime.

It is a super-2 number, since 2×51309031² = 5265233324317922, which contains 22 as substring.

Together with 51309029, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 51308993 and 51309011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51309331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25654515 + 25654516.

It is an arithmetic number, because the mean of its divisors is an integer number (25654516).

Almost surely, 2^51309031 is an apocalyptic number.

51309031 is a deficient number, since it is larger than the sum of its proper divisors (1).

51309031 is an equidigital number, since it uses as much as digits as its factorization.

51309031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 405, while the sum is 22.

The square root of 51309031 is about 7163.0322489851. The cubic root of 51309031 is about 371.5905016183.

Adding to 51309031 its reverse (13090315), we get a palindrome (64399346).

It can be divided in two parts, 5130 and 9031, that added together give a square (14161 = 119²).

The spelling of 51309031 in words is "fifty-one million, three hundred nine thousand, thirty-one".