51231261 has 8 divisors (see below), whose sum is σ = 68467840. Its totient is φ = 34074432.

The previous prime is 51231259. The next prime is 51231283. The reversal of 51231261 is 16213215.

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

It is not a de Polignac number, because 51231261 - 2¹ = 51231259 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51231211) 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, 18421 + ... + 21018.

It is an arithmetic number, because the mean of its divisors is an integer number (8558480).

Almost surely, 2^51231261 is an apocalyptic number.

It is an amenable number.

51231261 is a deficient number, since it is larger than the sum of its proper divisors (17236579).

51231261 is a wasteful number, since it uses less digits than its factorization.

51231261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39875.

The product of its digits is 360, while the sum is 21.

The square root of 51231261 is about 7157.6016234490. The cubic root of 51231261 is about 371.4026645991.

Adding to 51231261 its reverse (16213215), we get a palindrome (67444476).

The spelling of 51231261 in words is "fifty-one million, two hundred thirty-one thousand, two hundred sixty-one".