19129981 has 8 divisors (see below), whose sum is σ = 21813624. Its totient is φ = 16619520.

The previous prime is 19129963. The next prime is 19130011. The reversal of 19129981 is 18992191.

It can be written as a sum of positive squares in 4 ways, for example, as 931225 + 18198756 = 965^2 + 4266^2 .

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 19129981 - 2¹⁷ = 18998909 is a prime.

It is a super-2 number, since 2×19129981² = 731912346120722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19129931) 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, 43060 + ... + 43501.

It is an arithmetic number, because the mean of its divisors is an integer number (2726703).

Almost surely, 2^19129981 is an apocalyptic number.

It is an amenable number.

19129981 is a deficient number, since it is larger than the sum of its proper divisors (2683643).

19129981 is a wasteful number, since it uses less digits than its factorization.

19129981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86591.

The product of its digits is 11664, while the sum is 40.

The square root of 19129981 is about 4373.7833736938. The cubic root of 19129981 is about 267.4472764172.

The spelling of 19129981 in words is "nineteen million, one hundred twenty-nine thousand, nine hundred eighty-one".