19402081 has 4 divisors (see below), whose sum is σ = 19768212. Its totient is φ = 19035952.

The previous prime is 19402079. The next prime is 19402121. The reversal of 19402081 is 18020491.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9511056 + 9891025 = 3084^2 + 3145^2 .

It is a cyclic number.

It is not a de Polignac number, because 19402081 - 2¹ = 19402079 is a prime.

It is a super-2 number, since 2×19402081² = 752881494261122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19402051) 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, 182986 + ... + 183091.

It is an arithmetic number, because the mean of its divisors is an integer number (4942053).

Almost surely, 2^19402081 is an apocalyptic number.

It is an amenable number.

19402081 is a deficient number, since it is larger than the sum of its proper divisors (366131).

19402081 is an equidigital number, since it uses as much as digits as its factorization.

19402081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 366130.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 19402081 is about 4404.7793361302. The cubic root of 19402081 is about 268.7093454999.

The spelling of 19402081 in words is "nineteen million, four hundred two thousand, eighty-one".