1961981318 has 16 divisors (see below), whose sum is σ = 3240523584. Its totient is φ = 883473960.

The previous prime is 1961981317. The next prime is 1961981321. The reversal of 1961981318 is 8131891691.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1961981317) 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 7 ways as a sum of consecutive naturals, for example, 414380 + ... + 419087.

It is an arithmetic number, because the mean of its divisors is an integer number (202532724).

Almost surely, 2^1961981318 is an apocalyptic number.

1961981318 is a deficient number, since it is larger than the sum of its proper divisors (1278542266).

1961981318 is a wasteful number, since it uses less digits than its factorization.

1961981318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 833587.

The product of its digits is 93312, while the sum is 47.

The square root of 1961981318 is about 44294.2582960817. The cubic root of 1961981318 is about 1251.8864993040.

The spelling of 1961981318 in words is "one billion, nine hundred sixty-one million, nine hundred eighty-one thousand, three hundred eighteen".