19906651 has 2 divisors, whose sum is σ = 19906652. Its totient is φ = 19906650.

The previous prime is 19906639. The next prime is 19906687. The reversal of 19906651 is 15660991.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19906651 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19906651.

It is not a weakly prime, because it can be changed into another prime (19906351) 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, 9953325 + 9953326.

It is an arithmetic number, because the mean of its divisors is an integer number (9953326).

Almost surely, 2^19906651 is an apocalyptic number.

19906651 is a deficient number, since it is larger than the sum of its proper divisors (1).

19906651 is an equidigital number, since it uses as much as digits as its factorization.

19906651 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14580, while the sum is 37.

The square root of 19906651 is about 4461.6870127789. The cubic root of 19906651 is about 271.0187892911.

The spelling of 19906651 in words is "nineteen million, nine hundred six thousand, six hundred fifty-one".