18213324731 has 16 divisors (see below), whose sum is σ = 22043404800. Its totient is φ = 14690601600.

The previous prime is 18213324719. The next prime is 18213324739. The reversal of 18213324731 is 13742331281.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 18213324731 - 2⁶ = 18213324667 is a prime.

It is a super-2 number, since 2×18213324731² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18213324691 and 18213324700.

It is not an unprimeable number, because it can be changed into a prime (18213324739) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1056620 + ... + 1073718.

It is an arithmetic number, because the mean of its divisors is an integer number (1377712800).

Almost surely, 2^18213324731 is an apocalyptic number.

18213324731 is a deficient number, since it is larger than the sum of its proper divisors (3830080069).

18213324731 is a wasteful number, since it uses less digits than its factorization.

18213324731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26074.

The product of its digits is 24192, while the sum is 35.

The spelling of 18213324731 in words is "eighteen billion, two hundred thirteen million, three hundred twenty-four thousand, seven hundred thirty-one".