155215720 has 64 divisors (see below), whose sum is σ = 387296640. Its totient is φ = 55507200.

The previous prime is 155215691. The next prime is 155215721. The reversal of 155215720 is 27512551.

It is not an unprimeable number, because it can be changed into a prime (155215721) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 23949 + ... + 29731.

It is an arithmetic number, because the mean of its divisors is an integer number (6051510).

Almost surely, 2^155215720 is an apocalyptic number.

155215720 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 155215720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (193648320).

155215720 is an abundant number, since it is smaller than the sum of its proper divisors (232080920).

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

155215720 is a wasteful number, since it uses less digits than its factorization.

155215720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5866 (or 5862 counting only the distinct ones).

The product of its (nonzero) digits is 3500, while the sum is 28.

The square root of 155215720 is about 12458.5601094187. The cubic root of 155215720 is about 537.4176199689.

The spelling of 155215720 in words is "one hundred fifty-five million, two hundred fifteen thousand, seven hundred twenty".