51861331 has 2 divisors, whose sum is σ = 51861332. Its totient is φ = 51861330.

The previous prime is 51861319. The next prime is 51861361. The reversal of 51861331 is 13316815.

51861331 is nontrivially palindromic in base 4.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51861331 - 2⁹ = 51860819 is a prime.

It is a super-2 number, since 2×51861331² = 5379195306183122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 51861331.

It is not a weakly prime, because it can be changed into another prime (51861361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25930665 + 25930666.

It is an arithmetic number, because the mean of its divisors is an integer number (25930666).

Almost surely, 2^51861331 is an apocalyptic number.

51861331 is a deficient number, since it is larger than the sum of its proper divisors (1).

51861331 is an equidigital number, since it uses as much as digits as its factorization.

51861331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 28.

The square root of 51861331 is about 7201.4811670933. The cubic root of 51861331 is about 372.9190359673.

The spelling of 51861331 in words is "fifty-one million, eight hundred sixty-one thousand, three hundred thirty-one".