19670981 has 4 divisors (see below), whose sum is σ = 21459264. Its totient is φ = 17882700.

The previous prime is 19670977. The next prime is 19670983. The reversal of 19670981 is 18907691.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18907691 = 11 ⋅1718881.

It is not a de Polignac number, because 19670981 - 2² = 19670977 is a prime.

It is a super-2 number, since 2×19670981² = 773894987004722, 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 (19670983) 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, 894125 + ... + 894146.

It is an arithmetic number, because the mean of its divisors is an integer number (5364816).

Almost surely, 2^19670981 is an apocalyptic number.

19670981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

19670981 is a deficient number, since it is larger than the sum of its proper divisors (1788283).

19670981 is a wasteful number, since it uses less digits than its factorization.

19670981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1788282.

The product of its (nonzero) digits is 27216, while the sum is 41.

The square root of 19670981 is about 4435.1979662694. The cubic root of 19670981 is about 269.9450322487.

The spelling of 19670981 in words is "nineteen million, six hundred seventy thousand, nine hundred eighty-one".