19742819 has 4 divisors (see below), whose sum is σ = 19761096. Its totient is φ = 19724544.

The previous prime is 19742813. The next prime is 19742869. The reversal of 19742819 is 91824791.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19742819 - 2⁴ = 19742803 is a prime.

It is a super-2 number, since 2×19742819² = 779557804133522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19742813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7409 + ... + 9714.

It is an arithmetic number, because the mean of its divisors is an integer number (4940274).

Almost surely, 2^19742819 is an apocalyptic number.

19742819 is a deficient number, since it is larger than the sum of its proper divisors (18277).

19742819 is a wasteful number, since it uses less digits than its factorization.

19742819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18276.

The product of its digits is 36288, while the sum is 41.

The square root of 19742819 is about 4443.2892095834. The cubic root of 19742819 is about 270.2732441841.

The spelling of 19742819 in words is "nineteen million, seven hundred forty-two thousand, eight hundred nineteen".