19742861 has 4 divisors (see below), whose sum is σ = 19790400. Its totient is φ = 19695324.

The previous prime is 19742813. The next prime is 19742869. The reversal of 19742861 is 16824791.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19742861 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19742869) 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, 23141 + ... + 23978.

It is an arithmetic number, because the mean of its divisors is an integer number (4947600).

Almost surely, 2^19742861 is an apocalyptic number.

It is an amenable number.

19742861 is a deficient number, since it is larger than the sum of its proper divisors (47539).

19742861 is an equidigital number, since it uses as much as digits as its factorization.

19742861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47538.

The product of its digits is 24192, while the sum is 38.

The square root of 19742861 is about 4443.2939358093. The cubic root of 19742861 is about 270.2734358398.

The spelling of 19742861 in words is "nineteen million, seven hundred forty-two thousand, eight hundred sixty-one".