51663979 has 2 divisors, whose sum is σ = 51663980. Its totient is φ = 51663978.

The previous prime is 51663973. The next prime is 51664001. The reversal of 51663979 is 97936615.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51663979 - 2⁵ = 51663947 is a prime.

It is a super-2 number, since 2×51663979² = 5338333452224882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (51663973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25831989 + 25831990.

It is an arithmetic number, because the mean of its divisors is an integer number (25831990).

Almost surely, 2^51663979 is an apocalyptic number.

51663979 is a deficient number, since it is larger than the sum of its proper divisors (1).

51663979 is an equidigital number, since it uses as much as digits as its factorization.

51663979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 306180, while the sum is 46.

The square root of 51663979 is about 7187.7659255154. The cubic root of 51663979 is about 372.4454019644.

The spelling of 51663979 in words is "fifty-one million, six hundred sixty-three thousand, nine hundred seventy-nine".