155055245521 has 4 divisors (see below), whose sum is σ = 169151176944. Its totient is φ = 140959314100.

The previous prime is 155055245497. The next prime is 155055245539. The reversal of 155055245521 is 125542550551.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 125542550551 = 11 ⋅11412959141.

It is not a de Polignac number, because 155055245521 - 2²⁹ = 154518374609 is a prime.

It is a super-2 number, since 2×155055245521² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155055245021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7047965695 + ... + 7047965716.

It is an arithmetic number, because the mean of its divisors is an integer number (42287794236).

Almost surely, 2^155055245521 is an apocalyptic number.

155055245521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

155055245521 is a deficient number, since it is larger than the sum of its proper divisors (14095931423).

155055245521 is a wasteful number, since it uses less digits than its factorization.

155055245521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14095931422.

The product of its (nonzero) digits is 250000, while the sum is 40.

The spelling of 155055245521 in words is "one hundred fifty-five billion, fifty-five million, two hundred forty-five thousand, five hundred twenty-one".