1321125120 has 576 divisors, whose sum is σ = 5525667840. Its totient is φ = 292626432.

The previous prime is 1321125089. The next prime is 1321125121. The reversal of 1321125120 is 215211231.

It is a tau number, because it is divible by the number of its divisors (576).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1321125093 and 1321125102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321125121) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 10402497 + ... + 10402623.

Almost surely, 2^1321125120 is an apocalyptic number.

1321125120 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 1321125120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2762833920).

1321125120 is an abundant number, since it is smaller than the sum of its proper divisors (4204542720).

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

1321125120 is a wasteful number, since it uses less digits than its factorization.

1321125120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207 (or 187 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 1321125120 is about 36347.2849054782. The cubic root of 1321125120 is about 1097.2728919536.

Adding to 1321125120 its reverse (215211231), we get a palindrome (1536336351).

The spelling of 1321125120 in words is "one billion, three hundred twenty-one million, one hundred twenty-five thousand, one hundred twenty".