155236121 has 2 divisors, whose sum is σ = 155236122. Its totient is φ = 155236120.

The previous prime is 155236087. The next prime is 155236153. The reversal of 155236121 is 121632551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 92256025 + 62980096 = 9605^2 + 7936^2 .

It is a cyclic number.

It is not a de Polignac number, because 155236121 - 2²² = 151041817 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is equal to p_8722070 and since 155236121 and 8722070 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (155236171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77618060 + 77618061.

It is an arithmetic number, because the mean of its divisors is an integer number (77618061).

Almost surely, 2^155236121 is an apocalyptic number.

It is an amenable number.

155236121 is a deficient number, since it is larger than the sum of its proper divisors (1).

155236121 is an equidigital number, since it uses as much as digits as its factorization.

155236121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1800, while the sum is 26.

The square root of 155236121 is about 12459.3788368442. The cubic root of 155236121 is about 537.4411643550.

Adding to 155236121 its reverse (121632551), we get a palindrome (276868672).

It can be divided in two parts, 155236 and 121, that multiplied together give a square (18783556 = 4334²).

The spelling of 155236121 in words is "one hundred fifty-five million, two hundred thirty-six thousand, one hundred twenty-one".