31800225161 has 2 divisors, whose sum is σ = 31800225162. Its totient is φ = 31800225160.

The previous prime is 31800225151. The next prime is 31800225217. The reversal of 31800225161 is 16152200813.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30204702025 + 1595523136 = 173795^2 + 39944^2 .

It is a cyclic number.

It is not a de Polignac number, because 31800225161 - 2²² = 31796030857 is a prime.

It is a super-2 number, since 2×31800225161² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31800225151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15900112580 + 15900112581.

It is an arithmetic number, because the mean of its divisors is an integer number (15900112581).

Almost surely, 2^31800225161 is an apocalyptic number.

It is an amenable number.

31800225161 is a deficient number, since it is larger than the sum of its proper divisors (1).

31800225161 is an equidigital number, since it uses as much as digits as its factorization.

31800225161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 29.

Adding to 31800225161 its reverse (16152200813), we get a palindrome (47952425974).

The spelling of 31800225161 in words is "thirty-one billion, eight hundred million, two hundred twenty-five thousand, one hundred sixty-one".