155121129 has 16 divisors (see below), whose sum is σ = 230106240. Its totient is φ = 103280400.

The previous prime is 155121121. The next prime is 155121133. The reversal of 155121129 is 921121551.

It is not a de Polignac number, because 155121129 - 2³ = 155121121 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (155121121) 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, 20404 + ... + 26954.

It is an arithmetic number, because the mean of its divisors is an integer number (14381640).

Almost surely, 2^155121129 is an apocalyptic number.

It is an amenable number.

155121129 is a deficient number, since it is larger than the sum of its proper divisors (74985111).

155121129 is an equidigital number, since it uses as much as digits as its factorization.

155121129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7437 (or 7431 counting only the distinct ones).

The product of its digits is 900, while the sum is 27.

The square root of 155121129 is about 12454.7633056594. The cubic root of 155121129 is about 537.3084274203.

It can be divided in two parts, 15512 and 1129, that added together give a square (16641 = 129²).

The spelling of 155121129 in words is "one hundred fifty-five million, one hundred twenty-one thousand, one hundred twenty-nine".