19912499 has 2 divisors, whose sum is σ = 19912500. Its totient is φ = 19912498.

The previous prime is 19912493. The next prime is 19912517. The reversal of 19912499 is 99421991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19912499 - 2¹² = 19908403 is a prime.

It is not a weakly prime, because it can be changed into another prime (19912493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9956249 + 9956250.

It is an arithmetic number, because the mean of its divisors is an integer number (9956250).

Almost surely, 2^19912499 is an apocalyptic number.

19912499 is a deficient number, since it is larger than the sum of its proper divisors (1).

19912499 is an equidigital number, since it uses as much as digits as its factorization.

19912499 is an evil number, because the sum of its binary digits is even.

The product of its digits is 52488, while the sum is 44.

The square root of 19912499 is about 4462.3423221443. The cubic root of 19912499 is about 271.0453258609.

The spelling of 19912499 in words is "nineteen million, nine hundred twelve thousand, four hundred ninety-nine".