155655221 has 8 divisors (see below), whose sum is σ = 157536960. Its totient is φ = 153779328.

The previous prime is 155655187. The next prime is 155655233. The reversal of 155655221 is 122556551.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 155655221 - 2¹⁴ = 155638837 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 (155654221) 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 7 ways as a sum of consecutive naturals, for example, 75320 + ... + 77358.

It is an arithmetic number, because the mean of its divisors is an integer number (19692120).

Almost surely, 2^155655221 is an apocalyptic number.

It is an amenable number.

155655221 is a deficient number, since it is larger than the sum of its proper divisors (1881739).

155655221 is an equidigital number, since it uses as much as digits as its factorization.

155655221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2923.

The product of its digits is 15000, while the sum is 32.

The square root of 155655221 is about 12476.1861560334. The cubic root of 155655221 is about 537.9243834983.

The spelling of 155655221 in words is "one hundred fifty-five million, six hundred fifty-five thousand, two hundred twenty-one".