19603981 has 4 divisors (see below), whose sum is σ = 20456352. Its totient is φ = 18751612.

The previous prime is 19603979. The next prime is 19604021. The reversal of 19603981 is 18930691.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 19603981 - 2¹ = 19603979 is a prime.

It is a super-2 number, since 2×19603981² = 768632142096722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19603981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19603951) 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, 426151 + ... + 426196.

It is an arithmetic number, because the mean of its divisors is an integer number (5114088).

Almost surely, 2^19603981 is an apocalyptic number.

It is an amenable number.

19603981 is a deficient number, since it is larger than the sum of its proper divisors (852371).

19603981 is an equidigital number, since it uses as much as digits as its factorization.

19603981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 852370.

The product of its (nonzero) digits is 11664, while the sum is 37.

The square root of 19603981 is about 4427.6383095280. The cubic root of 19603981 is about 269.6382031129.

The spelling of 19603981 in words is "nineteen million, six hundred three thousand, nine hundred eighty-one".