51978869 has 2 divisors, whose sum is σ = 51978870. Its totient is φ = 51978868.

The previous prime is 51978863. The next prime is 51978923. The reversal of 51978869 is 96887915.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 33814225 + 18164644 = 5815^2 + 4262^2 .

It is a cyclic number.

It is not a de Polignac number, because 51978869 - 2¹² = 51974773 is a prime.

It is a super-2 number, since 2×51978869² = 5403605645038322, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51978869.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51978863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25989434 + 25989435.

It is an arithmetic number, because the mean of its divisors is an integer number (25989435).

Almost surely, 2^51978869 is an apocalyptic number.

It is an amenable number.

51978869 is a deficient number, since it is larger than the sum of its proper divisors (1).

51978869 is an equidigital number, since it uses as much as digits as its factorization.

51978869 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1088640, while the sum is 53.

The square root of 51978869 is about 7209.6372308182. The cubic root of 51978869 is about 373.2005500540.

The spelling of 51978869 in words is "fifty-one million, nine hundred seventy-eight thousand, eight hundred sixty-nine".