18036893581 has 12 divisors (see below), whose sum is σ = 21059706780. Its totient is φ = 15402710400.

The previous prime is 18036893531. The next prime is 18036893603. The reversal of 18036893581 is 18539863081.

It can be written as a sum of positive squares in 2 ways, for example, as 9023100100 + 9013793481 = 94990^2 + 94941^2 .

It is not a de Polignac number, because 18036893581 - 2¹³ = 18036885389 is a prime.

It is a super-2 number, since 2×18036893581² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18036893521) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 671020 + ... + 697381.

It is an arithmetic number, because the mean of its divisors is an integer number (1754975565).

Almost surely, 2^18036893581 is an apocalyptic number.

It is an amenable number.

18036893581 is a deficient number, since it is larger than the sum of its proper divisors (3022813199).

18036893581 is a wasteful number, since it uses less digits than its factorization.

18036893581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1368684 (or 1368677 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 52.

The spelling of 18036893581 in words is "eighteen billion, thirty-six million, eight hundred ninety-three thousand, five hundred eighty-one".