19191923 has 2 divisors, whose sum is σ = 19191924. Its totient is φ = 19191922.

The previous prime is 19191917. The next prime is 19191947. The reversal of 19191923 is 32919191.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19191923 - 2¹² = 19187827 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (19191983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9595961 + 9595962.

It is an arithmetic number, because the mean of its divisors is an integer number (9595962).

Almost surely, 2^19191923 is an apocalyptic number.

19191923 is a deficient number, since it is larger than the sum of its proper divisors (1).

19191923 is an equidigital number, since it uses as much as digits as its factorization.

19191923 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4374, while the sum is 35.

The square root of 19191923 is about 4380.8587057790. The cubic root of 19191923 is about 267.7356260862.

The spelling of 19191923 in words is "nineteen million, one hundred ninety-one thousand, nine hundred twenty-three".