1981978094 has 8 divisors (see below), whose sum is σ = 2977466808. Its totient is φ = 989489160.

The previous prime is 1981978093. The next prime is 1981978127. The reversal of 1981978094 is 4908791891.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981978093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 748292 + ... + 750935.

It is an arithmetic number, because the mean of its divisors is an integer number (372183351).

Almost surely, 2^1981978094 is an apocalyptic number.

1981978094 is a deficient number, since it is larger than the sum of its proper divisors (995488714).

1981978094 is a wasteful number, since it uses less digits than its factorization.

1981978094 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1499890.

The product of its (nonzero) digits is 1306368, while the sum is 56.

The square root of 1981978094 is about 44519.4125522788. The cubic root of 1981978094 is about 1256.1252626196.

The spelling of 1981978094 in words is "one billion, nine hundred eighty-one million, nine hundred seventy-eight thousand, ninety-four".