155019091 has 2 divisors, whose sum is σ = 155019092. Its totient is φ = 155019090.

The previous prime is 155019089. The next prime is 155019101. The reversal of 155019091 is 190910551.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 155019091 - 2¹ = 155019089 is a prime.

Together with 155019089, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (155019001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77509545 + 77509546.

It is an arithmetic number, because the mean of its divisors is an integer number (77509546).

Almost surely, 2^155019091 is an apocalyptic number.

155019091 is a deficient number, since it is larger than the sum of its proper divisors (1).

155019091 is an equidigital number, since it uses as much as digits as its factorization.

155019091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2025, while the sum is 31.

The square root of 155019091 is about 12450.6662873920. Note that the first 3 decimals coincide. The cubic root of 155019091 is about 537.1905885343.

The spelling of 155019091 in words is "one hundred fifty-five million, nineteen thousand, ninety-one".