4020123181 has 2 divisors, whose sum is σ = 4020123182. Its totient is φ = 4020123180.

The previous prime is 4020123157. The next prime is 4020123187. The reversal of 4020123181 is 1813210204.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3461557225 + 558565956 = 58835^2 + 23634^2 .

It is a cyclic number.

It is not a de Polignac number, because 4020123181 - 2⁷ = 4020123053 is a prime.

It is a super-2 number, since 2×4020123181² = 32322780780827117522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4020123187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2010061590 + 2010061591.

It is an arithmetic number, because the mean of its divisors is an integer number (2010061591).

Almost surely, 2^4020123181 is an apocalyptic number.

It is an amenable number.

4020123181 is a deficient number, since it is larger than the sum of its proper divisors (1).

4020123181 is an equidigital number, since it uses as much as digits as its factorization.

4020123181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 4020123181 is about 63404.4413349727. The cubic root of 4020123181 is about 1590.0585636961.

Adding to 4020123181 its reverse (1813210204), we get a palindrome (5833333385).

The spelling of 4020123181 in words is "four billion, twenty million, one hundred twenty-three thousand, one hundred eighty-one".