155409891 has 16 divisors (see below), whose sum is σ = 255032064. Its totient is φ = 81974304.

The previous prime is 155409889. The next prime is 155409893. The reversal of 155409891 is 198904551.

It is an interprime number because it is at equal distance from previous prime (155409889) and next prime (155409893).

It is not a de Polignac number, because 155409891 - 2¹ = 155409889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (155409893) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 284361 + ... + 284906.

It is an arithmetic number, because the mean of its divisors is an integer number (15939504).

Almost surely, 2^155409891 is an apocalyptic number.

155409891 is a deficient number, since it is larger than the sum of its proper divisors (99622173).

155409891 is a wasteful number, since it uses less digits than its factorization.

155409891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 569290.

The product of its (nonzero) digits is 64800, while the sum is 42.

The square root of 155409891 is about 12466.3503480369. The cubic root of 155409891 is about 537.6416252724.

The spelling of 155409891 in words is "one hundred fifty-five million, four hundred nine thousand, eight hundred ninety-one".