155121017 has 4 divisors (see below), whose sum is σ = 155226000. Its totient is φ = 155016036.

The previous prime is 155121011. The next prime is 155121019. The reversal of 155121017 is 710121551.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 155121017 - 2²⁰ = 154072441 is a prime.

It is a super-2 number, since 2×155121017² = 48125059830228578, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 155120983 and 155121001.

It is not an unprimeable number, because it can be changed into a prime (155121011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50243 + ... + 53240.

It is an arithmetic number, because the mean of its divisors is an integer number (38806500).

Almost surely, 2^155121017 is an apocalyptic number.

It is an amenable number.

155121017 is a deficient number, since it is larger than the sum of its proper divisors (104983).

155121017 is a wasteful number, since it uses less digits than its factorization.

155121017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104982.

The product of its (nonzero) digits is 350, while the sum is 23.

The square root of 155121017 is about 12454.7588093869. The cubic root of 155121017 is about 537.3082981051.

Adding to 155121017 its reverse (710121551), we get a palindrome (865242568).

The spelling of 155121017 in words is "one hundred fifty-five million, one hundred twenty-one thousand, seventeen".