51205531 has 8 divisors (see below), whose sum is σ = 55548864. Its totient is φ = 46920000.

The previous prime is 51205519. The next prime is 51205541. The reversal of 51205531 is 13550215.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51205531 - 2¹¹ = 51203483 is a prime.

It is a super-2 number, since 2×51205531² = 5244012809983922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51205501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12595 + ... + 16156.

It is an arithmetic number, because the mean of its divisors is an integer number (6943608).

Almost surely, 2^51205531 is an apocalyptic number.

51205531 is a deficient number, since it is larger than the sum of its proper divisors (4343333).

51205531 is a wasteful number, since it uses less digits than its factorization.

51205531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28901.

The product of its (nonzero) digits is 750, while the sum is 22.

The square root of 51205531 is about 7155.8040079365. The cubic root of 51205531 is about 371.3404773679.

Adding to 51205531 its reverse (13550215), we get a palindrome (64755746).

The spelling of 51205531 in words is "fifty-one million, two hundred five thousand, five hundred thirty-one".