51566869 has 2 divisors, whose sum is σ = 51566870. Its totient is φ = 51566868.

The previous prime is 51566813. The next prime is 51566873. The reversal of 51566869 is 96866515.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45064369 + 6502500 = 6713^2 + 2550^2 .

It is a cyclic number.

It is not a de Polignac number, because 51566869 - 2¹⁵ = 51534101 is a prime.

It is a super-2 number, since 2×51566869² = 5318283956926322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51566269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25783434 + 25783435.

It is an arithmetic number, because the mean of its divisors is an integer number (25783435).

Almost surely, 2^51566869 is an apocalyptic number.

It is an amenable number.

51566869 is a deficient number, since it is larger than the sum of its proper divisors (1).

51566869 is an equidigital number, since it uses as much as digits as its factorization.

51566869 is an evil number, because the sum of its binary digits is even.

The product of its digits is 388800, while the sum is 46.

The square root of 51566869 is about 7181.0075198401. The cubic root of 51566869 is about 372.2119004126.

The spelling of 51566869 in words is "fifty-one million, five hundred sixty-six thousand, eight hundred sixty-nine".