155079221 has 4 divisors (see below), whose sum is σ = 169177344. Its totient is φ = 140981100.

The previous prime is 155079191. The next prime is 155079251. The reversal of 155079221 is 122970551.

It is a happy number.

155079221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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: 122970551 = 11 ⋅11179141.

It is an interprime number because it is at equal distance from previous prime (155079191) and next prime (155079251).

It is a cyclic number.

It is not a de Polignac number, because 155079221 - 2¹⁰ = 155078197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155079251) 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, 7049045 + ... + 7049066.

It is an arithmetic number, because the mean of its divisors is an integer number (42294336).

Almost surely, 2^155079221 is an apocalyptic number.

155079221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

155079221 is a deficient number, since it is larger than the sum of its proper divisors (14098123).

155079221 is a wasteful number, since it uses less digits than its factorization.

155079221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14098122.

The product of its (nonzero) digits is 6300, while the sum is 32.

The square root of 155079221 is about 12453.0807834849. The cubic root of 155079221 is about 537.2600360979.

The spelling of 155079221 in words is "one hundred fifty-five million, seventy-nine thousand, two hundred twenty-one".