19817242 has 4 divisors (see below), whose sum is σ = 29725866. Its totient is φ = 9908620.

The previous prime is 19817233. The next prime is 19817297. The reversal of 19817242 is 24271891.

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

It can be written as a sum of positive squares in only one way, i.e., 19175641 + 641601 = 4379^2 + 801^2 .

It is a junction number, because it is equal to n+sod(n) for n = 19817198 and 19817207.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4954309 + ... + 4954312.

Almost surely, 2^19817242 is an apocalyptic number.

19817242 is a deficient number, since it is larger than the sum of its proper divisors (9908624).

19817242 is an equidigital number, since it uses as much as digits as its factorization.

19817242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9908623.

The product of its digits is 8064, while the sum is 34.

The square root of 19817242 is about 4451.6560963309. The cubic root of 19817242 is about 270.6124278251.

The spelling of 19817242 in words is "nineteen million, eight hundred seventeen thousand, two hundred forty-two".