1242888181 has 2 divisors, whose sum is σ = 1242888182. Its totient is φ = 1242888180.

The previous prime is 1242888149. The next prime is 1242888187. The reversal of 1242888181 is 1818882421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1187147025 + 55741156 = 34455^2 + 7466^2 .

It is a cyclic number.

It is not a de Polignac number, because 1242888181 - 2⁵ = 1242888149 is a prime.

It is a super-2 number, since 2×1242888181² = 3089542060938977522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1242888187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621444090 + 621444091.

It is an arithmetic number, because the mean of its divisors is an integer number (621444091).

Almost surely, 2^1242888181 is an apocalyptic number.

It is an amenable number.

1242888181 is a deficient number, since it is larger than the sum of its proper divisors (1).

1242888181 is an equidigital number, since it uses as much as digits as its factorization.

1242888181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 65536, while the sum is 43.

The square root of 1242888181 is about 35254.6192859886. The cubic root of 1242888181 is about 1075.1705317349.

The spelling of 1242888181 in words is "one billion, two hundred forty-two million, eight hundred eighty-eight thousand, one hundred eighty-one".