1981182593 has 4 divisors (see below), whose sum is σ = 2133581268. Its totient is φ = 1828783920.

The previous prime is 1981182571. The next prime is 1981182629. The reversal of 1981182593 is 3952811891.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1110755584 + 870427009 = 33328^2 + 29503^2 .

It is a cyclic number.

It is not a de Polignac number, because 1981182593 - 2⁸ = 1981182337 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1981182293) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76199318 + ... + 76199343.

It is an arithmetic number, because the mean of its divisors is an integer number (533395317).

Almost surely, 2^1981182593 is an apocalyptic number.

1981182593 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1981182593 is a deficient number, since it is larger than the sum of its proper divisors (152398675).

1981182593 is a wasteful number, since it uses less digits than its factorization.

1981182593 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152398674.

The product of its digits is 155520, while the sum is 47.

The square root of 1981182593 is about 44510.4773396107. The cubic root of 1981182593 is about 1255.9571843036.

The spelling of 1981182593 in words is "one billion, nine hundred eighty-one million, one hundred eighty-two thousand, five hundred ninety-three".