19816641 has 12 divisors (see below), whose sum is σ = 30826068. Its totient is φ = 12194784.

The previous prime is 19816633. The next prime is 19816649. The reversal of 19816641 is 14661891.

It is a happy number.

19816641 is a `hidden beast` number, since 1 + 9 + 8 + 1 + 6 + 641 = 666.

It is an interprime number because it is at equal distance from previous prime (19816633) and next prime (19816649).

It can be written as a sum of positive squares in 2 ways, for example, as 4016016 + 15800625 = 2004^2 + 3975^2 .

It is not a de Polignac number, because 19816641 - 2³ = 19816633 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 19816596 and 19816605.

It is not an unprimeable number, because it can be changed into a prime (19816649) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 84570 + ... + 84803.

It is an arithmetic number, because the mean of its divisors is an integer number (2568839).

Almost surely, 2^19816641 is an apocalyptic number.

It is an amenable number.

19816641 is a deficient number, since it is larger than the sum of its proper divisors (11009427).

19816641 is a wasteful number, since it uses less digits than its factorization.

19816641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169392 (or 169389 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 19816641 is about 4451.5885928509. The cubic root of 19816641 is about 270.6096921650.

The spelling of 19816641 in words is "nineteen million, eight hundred sixteen thousand, six hundred forty-one".