51819997 has 2 divisors, whose sum is σ = 51819998. Its totient is φ = 51819996.

The previous prime is 51819959. The next prime is 51820001. The reversal of 51819997 is 79991815.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41100921 + 10719076 = 6411^2 + 3274^2 .

It is a cyclic number.

It is not a de Polignac number, because 51819997 - 2²³ = 43431389 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51819997.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51819947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25909998 + 25909999.

It is an arithmetic number, because the mean of its divisors is an integer number (25909999).

Almost surely, 2^51819997 is an apocalyptic number.

It is an amenable number.

51819997 is a deficient number, since it is larger than the sum of its proper divisors (1).

51819997 is an equidigital number, since it uses as much as digits as its factorization.

51819997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 204120, while the sum is 49.

The square root of 51819997 is about 7198.6107687525. The cubic root of 51819997 is about 372.8199362332.

The spelling of 51819997 in words is "fifty-one million, eight hundred nineteen thousand, nine hundred ninety-seven".