19881494 has 4 divisors (see below), whose sum is σ = 29822244. Its totient is φ = 9940746.

The previous prime is 19881487. The next prime is 19881497. The reversal of 19881494 is 49418891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 49418891 = 431 ⋅114661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19881497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4970372 + ... + 4970375.

It is an arithmetic number, because the mean of its divisors is an integer number (7455561).

Almost surely, 2^19881494 is an apocalyptic number.

19881494 is a deficient number, since it is larger than the sum of its proper divisors (9940750).

19881494 is an equidigital number, since it uses as much as digits as its factorization.

19881494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9940749.

The product of its digits is 82944, while the sum is 44.

The square root of 19881494 is about 4458.8668964211. The cubic root of 19881494 is about 270.9045746367.

The spelling of 19881494 in words is "nineteen million, eight hundred eighty-one thousand, four hundred ninety-four".