19439661 has 8 divisors (see below), whose sum is σ = 25947360. Its totient is φ = 12945872.

The previous prime is 19439639. The next prime is 19439683. The reversal of 19439661 is 16693491.

It is an interprime number because it is at equal distance from previous prime (19439639) and next prime (19439683).

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 19439661 - 2⁶ = 19439597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19439611) 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, 406 + ... + 6248.

It is an arithmetic number, because the mean of its divisors is an integer number (3243420).

Almost surely, 2^19439661 is an apocalyptic number.

It is an amenable number.

19439661 is a deficient number, since it is larger than the sum of its proper divisors (6507699).

19439661 is a wasteful number, since it uses less digits than its factorization.

19439661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6955.

The product of its digits is 34992, while the sum is 39.

The square root of 19439661 is about 4409.0430934614. The cubic root of 19439661 is about 268.8827218253.

It can be divided in two parts, 19439 and 661, that added together give a triangular number (20100 = T₂₀₀).

The spelling of 19439661 in words is "nineteen million, four hundred thirty-nine thousand, six hundred sixty-one".