19915963 has 2 divisors, whose sum is σ = 19915964. Its totient is φ = 19915962.

The previous prime is 19915957. The next prime is 19915967. The reversal of 19915963 is 36951991.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19915963 is a prime.

It is not a weakly prime, because it can be changed into another prime (19915967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9957981 + 9957982.

It is an arithmetic number, because the mean of its divisors is an integer number (9957982).

Almost surely, 2^19915963 is an apocalyptic number.

19915963 is a deficient number, since it is larger than the sum of its proper divisors (1).

19915963 is an equidigital number, since it uses as much as digits as its factorization.

19915963 is an evil number, because the sum of its binary digits is even.

The product of its digits is 65610, while the sum is 43.

The square root of 19915963 is about 4462.7304422293. The cubic root of 19915963 is about 271.0610420629.

The spelling of 19915963 in words is "nineteen million, nine hundred fifteen thousand, nine hundred sixty-three".