155520231 has 8 divisors (see below), whose sum is σ = 207879024. Its totient is φ = 103420800.

The previous prime is 155520229. The next prime is 155520241. The reversal of 155520231 is 132025551.

It is a happy number.

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

It is not a de Polignac number, because 155520231 - 2¹ = 155520229 is a prime.

It is a super-2 number, since 2×155520231² = 48373084500586722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155520221) 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, 63436 + ... + 65841.

It is an arithmetic number, because the mean of its divisors is an integer number (25984878).

Almost surely, 2^155520231 is an apocalyptic number.

155520231 is a deficient number, since it is larger than the sum of its proper divisors (52358793).

155520231 is a wasteful number, since it uses less digits than its factorization.

155520231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129681.

The product of its (nonzero) digits is 1500, while the sum is 24.

The square root of 155520231 is about 12470.7750761530. The cubic root of 155520231 is about 537.7688358430.

Adding to 155520231 its reverse (132025551), we get a palindrome (287545782).

The spelling of 155520231 in words is "one hundred fifty-five million, five hundred twenty thousand, two hundred thirty-one".