19665520951 has 2 divisors, whose sum is σ = 19665520952. Its totient is φ = 19665520950.

The previous prime is 19665520883. The next prime is 19665520957. The reversal of 19665520951 is 15902556691.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19665520951 - 2⁹ = 19665520439 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19665520895 and 19665520904.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19665520957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9832760475 + 9832760476.

It is an arithmetic number, because the mean of its divisors is an integer number (9832760476).

Almost surely, 2^19665520951 is an apocalyptic number.

19665520951 is a deficient number, since it is larger than the sum of its proper divisors (1).

19665520951 is an equidigital number, since it uses as much as digits as its factorization.

19665520951 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 729000, while the sum is 49.

The spelling of 19665520951 in words is "nineteen billion, six hundred sixty-five million, five hundred twenty thousand, nine hundred fifty-one".