155209680 has 120 divisors (see below), whose sum is σ = 528565128. Its totient is φ = 40808448.

The previous prime is 155209679. The next prime is 155209699. The reversal of 155209680 is 86902551.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 39087504 + 116122176 = 6252^2 + 10776^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent 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 23 ways as a sum of consecutive naturals, for example, 51084 + ... + 54036.

Almost surely, 2^155209680 is an apocalyptic number.

155209680 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 155209680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (264282564).

155209680 is an abundant number, since it is smaller than the sum of its proper divisors (373355448).

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

155209680 is a wasteful number, since it uses less digits than its factorization.

155209680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3045 (or 3036 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 155209680 is about 12458.3177034462. The cubic root of 155209680 is about 537.4106489298.

It can be divided in two parts, 15520 and 9680, that added together give a triangular number (25200 = T₂₂₄).

The spelling of 155209680 in words is "one hundred fifty-five million, two hundred nine thousand, six hundred eighty".