155641121 has 2 divisors, whose sum is σ = 155641122. Its totient is φ = 155641120.

The previous prime is 155641097. The next prime is 155641127. The reversal of 155641121 is 121146551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 151560721 + 4080400 = 12311^2 + 2020^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155641121 is a prime.

It is a super-2 number, since 2×155641121² = 48448317092273282, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (155641127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77820560 + 77820561.

It is an arithmetic number, because the mean of its divisors is an integer number (77820561).

Almost surely, 2^155641121 is an apocalyptic number.

It is an amenable number.

155641121 is a deficient number, since it is larger than the sum of its proper divisors (1).

155641121 is an equidigital number, since it uses as much as digits as its factorization.

155641121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1200, while the sum is 26.

The square root of 155641121 is about 12475.6210667045. The cubic root of 155641121 is about 537.9081404135.

Adding to 155641121 its reverse (121146551), we get a palindrome (276787672).

The spelling of 155641121 in words is "one hundred fifty-five million, six hundred forty-one thousand, one hundred twenty-one".