155531123 has 12 divisors (see below), whose sum is σ = 175332024. Its totient is φ = 136821600.

The previous prime is 155531111. The next prime is 155531137. The reversal of 155531123 is 321135551.

It is a happy number.

It is not a de Polignac number, because 155531123 - 2⁴ = 155531107 is a prime.

It is a super-2 number, since 2×155531123² = 48379860443282258, which contains 22 as substring.

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 155531092 and 155531101.

It is not an unprimeable number, because it can be changed into a prime (155531143) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3215 + ... + 17927.

It is an arithmetic number, because the mean of its divisors is an integer number (14611002).

Almost surely, 2^155531123 is an apocalyptic number.

155531123 is a deficient number, since it is larger than the sum of its proper divisors (19800901).

155531123 is a wasteful number, since it uses less digits than its factorization.

155531123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14786 (or 14755 counting only the distinct ones).

The product of its digits is 2250, while the sum is 26.

The square root of 155531123 is about 12471.2117695114. The cubic root of 155531123 is about 537.7813899255.

Adding to 155531123 its reverse (321135551), we get a palindrome (476666674).

The spelling of 155531123 in words is "one hundred fifty-five million, five hundred thirty-one thousand, one hundred twenty-three".