51540231 has 4 divisors (see below), whose sum is σ = 68720312. Its totient is φ = 34360152.

The previous prime is 51540211. The next prime is 51540233. The reversal of 51540231 is 13204515.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 51540231 - 2²² = 47345927 is a prime.

It is a super-2 number, since 2×51540231² = 5312790823066722, 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 = 51540198 and 51540207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51540233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8590036 + ... + 8590041.

It is an arithmetic number, because the mean of its divisors is an integer number (17180078).

Almost surely, 2^51540231 is an apocalyptic number.

51540231 is a deficient number, since it is larger than the sum of its proper divisors (17180081).

51540231 is a wasteful number, since it uses less digits than its factorization.

51540231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17180080.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 51540231 is about 7179.1525265870. The cubic root of 51540231 is about 372.1477979598.

Adding to 51540231 its reverse (13204515), we get a palindrome (64744746).

The spelling of 51540231 in words is "fifty-one million, five hundred forty thousand, two hundred thirty-one".