155840109 has 16 divisors (see below), whose sum is σ = 223380480. Its totient is φ = 96329520.

The previous prime is 155840107. The next prime is 155840117. The reversal of 155840109 is 901048551.

It is not a de Polignac number, because 155840109 - 2¹ = 155840107 is a prime.

It is a super-2 number, since 2×155840109² = 48572279146263762, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 155840109.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155840107) 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, 26407 + ... + 31764.

It is an arithmetic number, because the mean of its divisors is an integer number (13961280).

Almost surely, 2^155840109 is an apocalyptic number.

155840109 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

155840109 is a deficient number, since it is larger than the sum of its proper divisors (67540371).

155840109 is a wasteful number, since it uses less digits than its factorization.

155840109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58240.

The product of its (nonzero) digits is 7200, while the sum is 33.

The square root of 155840109 is about 12483.5935931926. The cubic root of 155840109 is about 538.1372822599.

The spelling of 155840109 in words is "one hundred fifty-five million, eight hundred forty thousand, one hundred nine".