1981782442 has 8 divisors (see below), whose sum is σ = 3101920416. Its totient is φ = 947808972.

The previous prime is 1981782433. The next prime is 1981782443. The reversal of 1981782442 is 2442871891.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Harshad number since it is a multiple of its sum of digits (46), and also a Moran number because the ratio is a prime number: 43082227 = 1981782442 / (1 + 9 + 8 + 1 + 7 + 8 + 2 + 4 + 4 + 2).

It is a junction number, because it is equal to n+sod(n) for n = 1981782392 and 1981782401.

It is not an unprimeable number, because it can be changed into a prime (1981782443) 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, 21541068 + ... + 21541159.

It is an arithmetic number, because the mean of its divisors is an integer number (387740052).

Almost surely, 2^1981782442 is an apocalyptic number.

1981782442 is a deficient number, since it is larger than the sum of its proper divisors (1120137974).

1981782442 is a wasteful number, since it uses less digits than its factorization.

1981782442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43082252.

The product of its digits is 258048, while the sum is 46.

The square root of 1981782442 is about 44517.2151195467. The cubic root of 1981782442 is about 1256.0839282395.

The spelling of 1981782442 in words is "one billion, nine hundred eighty-one million, seven hundred eighty-two thousand, four hundred forty-two".