155520420 has 192 divisors, whose sum is σ = 512096256. Its totient is φ = 34846720.

The previous prime is 155520373. The next prime is 155520451. The reversal of 155520420 is 24025551.

155520420 = 295² + 296² + ... + 789².

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 931177 + ... + 931343.

It is an arithmetic number, because the mean of its divisors is an integer number (2667168).

Almost surely, 2^155520420 is an apocalyptic number.

155520420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 155520420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (256048128).

155520420 is an abundant number, since it is smaller than the sum of its proper divisors (356575836).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

155520420 is a wasteful number, since it uses less digits than its factorization.

155520420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290 (or 288 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 24.

The square root of 155520420 is about 12470.7826538674. The cubic root of 155520420 is about 537.7690536888.

Adding to 155520420 its reverse (24025551), we get a palindrome (179545971).

The spelling of 155520420 in words is "one hundred fifty-five million, five hundred twenty thousand, four hundred twenty".