155540219 has 2 divisors, whose sum is σ = 155540220. Its totient is φ = 155540218.

The previous prime is 155540201. The next prime is 155540221. The reversal of 155540219 is 912045551.

It is a strong prime.

It is an emirp because it is prime and its reverse (912045551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 155540219 - 2²⁰ = 154491643 is a prime.

It is a super-2 number, since 2×155540219² = 48385519453135922, which contains 22 as substring.

Together with 155540221, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (155540239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77770109 + 77770110.

It is an arithmetic number, because the mean of its divisors is an integer number (77770110).

Almost surely, 2^155540219 is an apocalyptic number.

155540219 is a deficient number, since it is larger than the sum of its proper divisors (1).

155540219 is an equidigital number, since it uses as much as digits as its factorization.

155540219 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9000, while the sum is 32.

The square root of 155540219 is about 12471.5764440587. The cubic root of 155540219 is about 537.7918734953.

The spelling of 155540219 in words is "one hundred fifty-five million, five hundred forty thousand, two hundred nineteen".