51155813 has 2 divisors, whose sum is σ = 51155814. Its totient is φ = 51155812.

The previous prime is 51155807. The next prime is 51155827. The reversal of 51155813 is 31855115.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50438404 + 717409 = 7102^2 + 847^2 .

It is a cyclic number.

It is not a de Polignac number, because 51155813 - 2¹² = 51151717 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51155833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25577906 + 25577907.

It is an arithmetic number, because the mean of its divisors is an integer number (25577907).

Almost surely, 2^51155813 is an apocalyptic number.

It is an amenable number.

51155813 is a deficient number, since it is larger than the sum of its proper divisors (1).

51155813 is an equidigital number, since it uses as much as digits as its factorization.

51155813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3000, while the sum is 29.

The square root of 51155813 is about 7152.3292010365. The cubic root of 51155813 is about 371.2202541287.

The spelling of 51155813 in words is "fifty-one million, one hundred fifty-five thousand, eight hundred thirteen".