155051820 has 360 divisors, whose sum is σ = 616426272. Its totient is φ = 31933440.

The previous prime is 155051789. The next prime is 155051839. The reversal of 155051820 is 28150551.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 1372084 + ... + 1372196.

Almost surely, 2^155051820 is an apocalyptic number.

155051820 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 155051820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (308213136).

155051820 is an abundant number, since it is smaller than the sum of its proper divisors (461374452).

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

155051820 is a wasteful number, since it uses less digits than its factorization.

155051820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 27.

The square root of 155051820 is about 12451.9805653559. The cubic root of 155051820 is about 537.2283913483.

The spelling of 155051820 in words is "one hundred fifty-five million, fifty-one thousand, eight hundred twenty".