51115213 has 4 divisors (see below), whose sum is σ = 51130048. Its totient is φ = 51100380.

The previous prime is 51115199. The next prime is 51115231. The reversal of 51115213 is 31251115.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51115213 is a prime.

It is a super-2 number, since 2×51115213² = 5225530000070738, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51115513) 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, 748 + ... + 10138.

It is an arithmetic number, because the mean of its divisors is an integer number (12782512).

Almost surely, 2^51115213 is an apocalyptic number.

It is an amenable number.

51115213 is a deficient number, since it is larger than the sum of its proper divisors (14835).

51115213 is an equidigital number, since it uses as much as digits as its factorization.

51115213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14834.

The product of its digits is 150, while the sum is 19.

The square root of 51115213 is about 7149.4904014202. The cubic root of 51115213 is about 371.1220213611.

Adding to 51115213 its reverse (31251115), we get a palindrome (82366328).

The spelling of 51115213 in words is "fifty-one million, one hundred fifteen thousand, two hundred thirteen".