155340503221 has 4 divisors (see below), whose sum is σ = 163516319200. Its totient is φ = 147164687244.

The previous prime is 155340503189. The next prime is 155340503243. The reversal of 155340503221 is 122305043551.

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: 122305043551 = 907 ⋅134845693.

It is a cyclic number.

It is not a de Polignac number, because 155340503221 - 2⁵ = 155340503189 is a prime.

It is a super-2 number, since 2×155340503221² (a number of 23 digits) 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 (155340501221) 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, 4087907961 + ... + 4087907998.

It is an arithmetic number, because the mean of its divisors is an integer number (40879079800).

Almost surely, 2^155340503221 is an apocalyptic number.

It is an amenable number.

155340503221 is a deficient number, since it is larger than the sum of its proper divisors (8175815979).

155340503221 is an equidigital number, since it uses as much as digits as its factorization.

155340503221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8175815978.

The product of its (nonzero) digits is 18000, while the sum is 31.

Adding to 155340503221 its reverse (122305043551), we get a palindrome (277645546772).

The spelling of 155340503221 in words is "one hundred fifty-five billion, three hundred forty million, five hundred three thousand, two hundred twenty-one".