19649939 has 8 divisors (see below), whose sum is σ = 20367360. Its totient is φ = 18937800.

The previous prime is 19649899. The next prime is 19649953. The reversal of 19649939 is 93994691.

It is a happy number.

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 19649939 - 2¹⁶ = 19584403 is a prime.

It is a super-2 number, since 2×19649939² = 772240205407442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19649989) 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, 7232 + ... + 9570.

It is an arithmetic number, because the mean of its divisors is an integer number (2545920).

Almost surely, 2^19649939 is an apocalyptic number.

19649939 is a deficient number, since it is larger than the sum of its proper divisors (717421).

19649939 is a wasteful number, since it uses less digits than its factorization.

19649939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2641.

The product of its digits is 472392, while the sum is 50.

The square root of 19649939 is about 4432.8251713777. The cubic root of 19649939 is about 269.8487447286.

The spelling of 19649939 in words is "nineteen million, six hundred forty-nine thousand, nine hundred thirty-nine".