7801020181 has 2 divisors, whose sum is σ = 7801020182. Its totient is φ = 7801020180.

The previous prime is 7801020151. The next prime is 7801020187. The reversal of 7801020181 is 1810201087.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7252055281 + 548964900 = 85159^2 + 23430^2 .

It is an emirp because it is prime and its reverse (1810201087) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7801020181 - 2¹¹ = 7801018133 is a prime.

It is a super-2 number, since 2×7801020181² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7801020187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3900510090 + 3900510091.

It is an arithmetic number, because the mean of its divisors is an integer number (3900510091).

Almost surely, 2^7801020181 is an apocalyptic number.

It is an amenable number.

7801020181 is a deficient number, since it is larger than the sum of its proper divisors (1).

7801020181 is an equidigital number, since it uses as much as digits as its factorization.

7801020181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 896, while the sum is 28.

The square root of 7801020181 is about 88323.3841120232. The cubic root of 7801020181 is about 1983.2789411034.

The spelling of 7801020181 in words is "seven billion, eight hundred one million, twenty thousand, one hundred eighty-one".