321155120 has 160 divisors (see below), whose sum is σ = 892442880. Its totient is φ = 105937920.

The previous prime is 321155117. The next prime is 321155123. The reversal of 321155120 is 21551123.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (321155117) and next prime (321155123).

It is a super-2 number, since 2×321155120² = 206281222204428800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 321155092 and 321155101.

It is not an unprimeable number, because it can be changed into a prime (321155123) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 766271 + ... + 766689.

It is an arithmetic number, because the mean of its divisors is an integer number (5577768).

Almost surely, 2^321155120 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 321155120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (446221440).

321155120 is an abundant number, since it is smaller than the sum of its proper divisors (571287760).

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

321155120 is a wasteful number, since it uses less digits than its factorization.

321155120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523 (or 517 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 321155120 is about 17920.8013213695. The cubic root of 321155120 is about 684.8124017865.

The spelling of 321155120 in words is "three hundred twenty-one million, one hundred fifty-five thousand, one hundred twenty".