51305331 has 48 divisors (see below), whose sum is σ = 87605504. Its totient is φ = 26136000.

The previous prime is 51305329. The next prime is 51305351. The reversal of 51305331 is 13350315.

It is a happy number.

It is not a de Polignac number, because 51305331 - 2¹ = 51305329 is a prime.

It is a super-2 number, since 2×51305331² = 5264473978039122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 51305298 and 51305307.

It is not an unprimeable number, because it can be changed into a prime (51305311) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 154836 + ... + 155166.

Almost surely, 2^51305331 is an apocalyptic number.

51305331 is a deficient number, since it is larger than the sum of its proper divisors (36300173).

51305331 is a wasteful number, since it uses less digits than its factorization.

51305331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 424 (or 413 counting only the distinct ones).

The product of its (nonzero) digits is 675, while the sum is 21.

The square root of 51305331 is about 7162.7739738177. The cubic root of 51305331 is about 371.5815693512.

Adding to 51305331 its reverse (13350315), we get a palindrome (64655646).

The spelling of 51305331 in words is "fifty-one million, three hundred five thousand, three hundred thirty-one".