19749641 has 4 divisors (see below), whose sum is σ = 19945284. Its totient is φ = 19554000.

The previous prime is 19749637. The next prime is 19749661. The reversal of 19749641 is 14694791.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 14694791 = 2683 ⋅5477.

It can be written as a sum of positive squares in 2 ways, for example, as 10725625 + 9024016 = 3275^2 + 3004^2 .

It is a cyclic number.

It is not a de Polignac number, because 19749641 - 2² = 19749637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (19749661) 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, 97670 + ... + 97871.

It is an arithmetic number, because the mean of its divisors is an integer number (4986321).

Almost surely, 2^19749641 is an apocalyptic number.

It is an amenable number.

19749641 is a deficient number, since it is larger than the sum of its proper divisors (195643).

19749641 is a wasteful number, since it uses less digits than its factorization.

19749641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195642.

The product of its digits is 54432, while the sum is 41.

The square root of 19749641 is about 4444.0568178186. The cubic root of 19749641 is about 270.3043709741.

The spelling of 19749641 in words is "nineteen million, seven hundred forty-nine thousand, six hundred forty-one".