51866869 has 2 divisors, whose sum is σ = 51866870. Its totient is φ = 51866868.

The previous prime is 51866831. The next prime is 51866921. The reversal of 51866869 is 96866815.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27984100 + 23882769 = 5290^2 + 4887^2 .

It is a cyclic number.

It is not a de Polignac number, because 51866869 - 2¹⁹ = 51342581 is a prime.

It is a super-2 number, since 2×51866869² = 5380344199726322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51866809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25933434 + 25933435.

It is an arithmetic number, because the mean of its divisors is an integer number (25933435).

Almost surely, 2^51866869 is an apocalyptic number.

It is an amenable number.

51866869 is a deficient number, since it is larger than the sum of its proper divisors (1).

51866869 is an equidigital number, since it uses as much as digits as its factorization.

51866869 is an evil number, because the sum of its binary digits is even.

The product of its digits is 622080, while the sum is 49.

The square root of 51866869 is about 7201.8656610631. The cubic root of 51866869 is about 372.9323095186.

The spelling of 51866869 in words is "fifty-one million, eight hundred sixty-six thousand, eight hundred sixty-nine".