19790981 has 8 divisors (see below), whose sum is σ = 22648704. Its totient is φ = 16940880.

The previous prime is 19790921. The next prime is 19790983. The reversal of 19790981 is 18909791.

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 19790981 - 2⁶ = 19790917 is a prime.

It is a super-2 number, since 2×19790981² = 783365857884722, 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 (19790983) 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, 5696 + ... + 8486.

It is an arithmetic number, because the mean of its divisors is an integer number (2831088).

Almost surely, 2^19790981 is an apocalyptic number.

It is an amenable number.

19790981 is a deficient number, since it is larger than the sum of its proper divisors (2857723).

19790981 is a wasteful number, since it uses less digits than its factorization.

19790981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3811.

The product of its (nonzero) digits is 40824, while the sum is 44.

The square root of 19790981 is about 4448.7055420650. The cubic root of 19790981 is about 270.4928401384.

The spelling of 19790981 in words is "nineteen million, seven hundred ninety thousand, nine hundred eighty-one".