19797749 has 8 divisors (see below), whose sum is σ = 20532960. Its totient is φ = 19066096.

The previous prime is 19797727. The next prime is 19797781. The reversal of 19797749 is 94779791.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 19797749 - 2⁸ = 19797493 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 19797749.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19797049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16442 + ... + 17604.

It is an arithmetic number, because the mean of its divisors is an integer number (2566620).

Almost surely, 2^19797749 is an apocalyptic number.

It is an amenable number.

19797749 is a deficient number, since it is larger than the sum of its proper divisors (735211).

19797749 is a wasteful number, since it uses less digits than its factorization.

19797749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1779.

The product of its digits is 1000188, while the sum is 53.

The square root of 19797749 is about 4449.4661477530. The cubic root of 19797749 is about 270.5236704595.

The spelling of 19797749 in words is "nineteen million, seven hundred ninety-seven thousand, seven hundred forty-nine".