1981135412 has 6 divisors (see below), whose sum is σ = 3466986978. Its totient is φ = 990567704.

The previous prime is 1981135411. The next prime is 1981135421. The reversal of 1981135412 is 2145311891.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1568476816 + 412658596 = 39604^2 + 20314^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981135411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 247641923 + ... + 247641930.

It is an arithmetic number, because the mean of its divisors is an integer number (577831163).

Almost surely, 2^1981135412 is an apocalyptic number.

It is an amenable number.

1981135412 is a deficient number, since it is larger than the sum of its proper divisors (1485851566).

1981135412 is a wasteful number, since it uses less digits than its factorization.

1981135412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 495283857 (or 495283855 counting only the distinct ones).

The product of its digits is 8640, while the sum is 35.

The square root of 1981135412 is about 44509.9473376458. The cubic root of 1981135412 is about 1255.9472142001.

The spelling of 1981135412 in words is "one billion, nine hundred eighty-one million, one hundred thirty-five thousand, four hundred twelve".