19979690 has 8 divisors (see below), whose sum is σ = 35963460. Its totient is φ = 7991872.

The previous prime is 19979689. The next prime is 19979693. The reversal of 19979690 is 9697991.

It can be written as a sum of positive squares in 2 ways, for example, as 18498601 + 1481089 = 4301^2 + 1217^2 .

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

It is a super-2 number, since 2×19979690² = 798376024992200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (19979693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 998975 + ... + 998994.

Almost surely, 2^19979690 is an apocalyptic number.

19979690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19979690 is a deficient number, since it is larger than the sum of its proper divisors (15983770).

19979690 is a wasteful number, since it uses less digits than its factorization.

19979690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1997976.

The product of its (nonzero) digits is 275562, while the sum is 50.

The square root of 19979690 is about 4469.8646511947. The cubic root of 19979690 is about 271.3498475032.

The spelling of 19979690 in words is "nineteen million, nine hundred seventy-nine thousand, six hundred ninety".