1981954923 has 32 divisors (see below), whose sum is σ = 3033676800. Its totient is φ = 1140811776.

The previous prime is 1981954903. The next prime is 1981954967. The reversal of 1981954923 is 3294591891.

It is not a de Polignac number, because 1981954923 - 2¹² = 1981950827 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1981954903) 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 31 ways as a sum of consecutive naturals, for example, 41611 + ... + 75467.

It is an arithmetic number, because the mean of its divisors is an integer number (94802400).

Almost surely, 2^1981954923 is an apocalyptic number.

1981954923 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1981954923 is a deficient number, since it is larger than the sum of its proper divisors (1051721877).

1981954923 is a wasteful number, since it uses less digits than its factorization.

1981954923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33971.

The product of its digits is 699840, while the sum is 51.

The square root of 1981954923 is about 44519.1523167277. The cubic root of 1981954923 is about 1256.1203675449.

The spelling of 1981954923 in words is "one billion, nine hundred eighty-one million, nine hundred fifty-four thousand, nine hundred twenty-three".