155057261 has 2 divisors, whose sum is σ = 155057262. Its totient is φ = 155057260.

The previous prime is 155057239. The next prime is 155057263. The reversal of 155057261 is 162750551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 147161161 + 7896100 = 12131^2 + 2810^2 .

It is a cyclic number.

It is not a de Polignac number, because 155057261 - 2¹⁴ = 155040877 is a prime.

Together with 155057263, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155057263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77528630 + 77528631.

It is an arithmetic number, because the mean of its divisors is an integer number (77528631).

Almost surely, 2^155057261 is an apocalyptic number.

It is an amenable number.

155057261 is a deficient number, since it is larger than the sum of its proper divisors (1).

155057261 is an equidigital number, since it uses as much as digits as its factorization.

155057261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10500, while the sum is 32.

The square root of 155057261 is about 12452.1990427394. The cubic root of 155057261 is about 537.2346753237.

The spelling of 155057261 in words is "one hundred fifty-five million, fifty-seven thousand, two hundred sixty-one".