51278761 has 2 divisors, whose sum is σ = 51278762. Its totient is φ = 51278760.

The previous prime is 51278713. The next prime is 51278789. The reversal of 51278761 is 16787215.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48038761 + 3240000 = 6931^2 + 1800^2 .

It is a cyclic number.

It is not a de Polignac number, because 51278761 - 2¹¹ = 51276713 is a prime.

It is a super-2 number, since 2×51278761² = 5259022659390242, 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 51278761.

It is not a weakly prime, because it can be changed into another prime (51278791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25639380 + 25639381.

It is an arithmetic number, because the mean of its divisors is an integer number (25639381).

Almost surely, 2^51278761 is an apocalyptic number.

It is an amenable number.

51278761 is a deficient number, since it is larger than the sum of its proper divisors (1).

51278761 is an equidigital number, since it uses as much as digits as its factorization.

51278761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23520, while the sum is 37.

The square root of 51278761 is about 7160.9190052674. The cubic root of 51278761 is about 371.5174133988.

The spelling of 51278761 in words is "fifty-one million, two hundred seventy-eight thousand, seven hundred sixty-one".