1981955613 has 32 divisors (see below), whose sum is σ = 3051671040. Its totient is φ = 1132770240.

The previous prime is 1981955567. The next prime is 1981955627. The reversal of 1981955613 is 3165591891.

1981955613 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1981955613 - 2¹⁶ = 1981890077 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981955413) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17070 + ... + 65232.

It is an arithmetic number, because the mean of its divisors is an integer number (95364720).

Almost surely, 2^1981955613 is an apocalyptic number.

It is an amenable number.

1981955613 is a deficient number, since it is larger than the sum of its proper divisors (1069715427).

1981955613 is a wasteful number, since it uses less digits than its factorization.

1981955613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48249.

The product of its digits is 291600, while the sum is 48.

The square root of 1981955613 is about 44519.1600662007. The cubic root of 1981955613 is about 1256.1205133140.

The spelling of 1981955613 in words is "one billion, nine hundred eighty-one million, nine hundred fifty-five thousand, six hundred thirteen".