19642861 has 4 divisors (see below), whose sum is σ = 22448992. Its totient is φ = 16836732.

The previous prime is 19642853. The next prime is 19642877. The reversal of 19642861 is 16824691.

It is a happy number.

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 not a de Polignac number, because 19642861 - 2³ = 19642853 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19642861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19642801) 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, 1403055 + ... + 1403068.

It is an arithmetic number, because the mean of its divisors is an integer number (5612248).

Almost surely, 2^19642861 is an apocalyptic number.

It is an amenable number.

19642861 is a deficient number, since it is larger than the sum of its proper divisors (2806131).

19642861 is an equidigital number, since it uses as much as digits as its factorization.

19642861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2806130.

The product of its digits is 20736, while the sum is 37.

The square root of 19642861 is about 4432.0267372840. The cubic root of 19642861 is about 269.8163405773.

It can be divided in two parts, 19642 and 861, that added together give a triangular number (20503 = T₂₀₂).

The spelling of 19642861 in words is "nineteen million, six hundred forty-two thousand, eight hundred sixty-one".