155110021 has 12 divisors (see below), whose sum is σ = 170989056. Its totient is φ = 140598920.

The previous prime is 155110013. The next prime is 155110051. The reversal of 155110021 is 120011551.

155110021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 155110021 - 2³ = 155110013 is a prime.

It is a super-2 number, since 2×155110021² = 48118237229240882, 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 = 155109977 and 155110004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155110051) 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, 44670 + ... + 48016.

It is an arithmetic number, because the mean of its divisors is an integer number (14249088).

Almost surely, 2^155110021 is an apocalyptic number.

155110021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

155110021 is a deficient number, since it is larger than the sum of its proper divisors (15879035).

155110021 is a wasteful number, since it uses less digits than its factorization.

155110021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3752 (or 3741 counting only the distinct ones).

The product of its (nonzero) digits is 50, while the sum is 16.

The square root of 155110021 is about 12454.3173638702. The cubic root of 155110021 is about 537.2956018207.

Adding to 155110021 its reverse (120011551), we get a palindrome (275121572).

The spelling of 155110021 in words is "one hundred fifty-five million, one hundred ten thousand, twenty-one".