155353021 has 4 divisors (see below), whose sum is σ = 164491452. Its totient is φ = 146214592.

The previous prime is 155353007. The next prime is 155353027. The reversal of 155353021 is 120353551.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120353551 = 10631 ⋅11321.

It can be written as a sum of positive squares in 2 ways, for example, as 144264121 + 11088900 = 12011^2 + 3330^2 .

It is a cyclic number.

It is not a de Polignac number, because 155353021 - 2²³ = 146964413 is a prime.

It is a super-2 number, since 2×155353021² = 48269122267652882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155353027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4569190 + ... + 4569223.

It is an arithmetic number, because the mean of its divisors is an integer number (41122863).

Almost surely, 2^155353021 is an apocalyptic number.

It is an amenable number.

155353021 is a deficient number, since it is larger than the sum of its proper divisors (9138431).

155353021 is an equidigital number, since it uses as much as digits as its factorization.

155353021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9138430.

The product of its (nonzero) digits is 2250, while the sum is 25.

The square root of 155353021 is about 12464.0691991019. The cubic root of 155353021 is about 537.5760365480.

It can be divided in two parts, 1553530 and 21, that added together give a palindrome (1553551).

The spelling of 155353021 in words is "one hundred fifty-five million, three hundred fifty-three thousand, twenty-one".