155077780 has 144 divisors (see below), whose sum is σ = 397704384. Its totient is φ = 50319360.

The previous prime is 155077763. The next prime is 155077807. The reversal of 155077780 is 87770551.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 1598692 + ... + 1598788.

It is an arithmetic number, because the mean of its divisors is an integer number (2761836).

Almost surely, 2^155077780 is an apocalyptic number.

155077780 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 155077780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (198852192).

155077780 is an abundant number, since it is smaller than the sum of its proper divisors (242626604).

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

155077780 is a wasteful number, since it uses less digits than its factorization.

155077780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186 (or 171 counting only the distinct ones).

The product of its (nonzero) digits is 68600, while the sum is 40.

The square root of 155077780 is about 12453.0229261814. The cubic root of 155077780 is about 537.2583720149.

The spelling of 155077780 in words is "one hundred fifty-five million, seventy-seven thousand, seven hundred eighty".