19979638 has 8 divisors (see below), whose sum is σ = 34250832. Its totient is φ = 8562696.

The previous prime is 19979633. The next prime is 19979647. The reversal of 19979638 is 83697991.

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

It is a super-2 number, since 2×19979638² = 798371869222088, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19979633) 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, 713545 + ... + 713572.

It is an arithmetic number, because the mean of its divisors is an integer number (4281354).

Almost surely, 2^19979638 is an apocalyptic number.

19979638 is a deficient number, since it is larger than the sum of its proper divisors (14271194).

19979638 is a wasteful number, since it uses less digits than its factorization.

19979638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1427126.

The product of its digits is 734832, while the sum is 52.

The square root of 19979638 is about 4469.8588344600. The cubic root of 19979638 is about 271.3496120941.

The spelling of 19979638 in words is "nineteen million, nine hundred seventy-nine thousand, six hundred thirty-eight".