155204261 has 2 divisors, whose sum is σ = 155204262. Its totient is φ = 155204260.

The previous prime is 155204251. The next prime is 155204263. The reversal of 155204261 is 162402551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 93973636 + 61230625 = 9694^2 + 7825^2 .

It is an emirp because it is prime and its reverse (162402551) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155204261 is a prime.

It is a super-2 number, since 2×155204261² = 48176725265112242, which contains 22 as substring.

Together with 155204263, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 155204261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155204263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77602130 + 77602131.

It is an arithmetic number, because the mean of its divisors is an integer number (77602131).

Almost surely, 2^155204261 is an apocalyptic number.

It is an amenable number.

155204261 is a deficient number, since it is larger than the sum of its proper divisors (1).

155204261 is an equidigital number, since it uses as much as digits as its factorization.

155204261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 155204261 is about 12458.1002163251. The cubic root of 155204261 is about 537.4043944612.

The spelling of 155204261 in words is "one hundred fifty-five million, two hundred four thousand, two hundred sixty-one".