1211312320 has 112 divisors (see below), whose sum is σ = 3051352800. Its totient is φ = 456744960.

The previous prime is 1211312317. The next prime is 1211312351. The reversal of 1211312320 is 232131121.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 1211312294 and 1211312303.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1708126 + ... + 1708834.

Almost surely, 2^1211312320 is an apocalyptic number.

1211312320 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 1211312320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1525676400).

1211312320 is an abundant number, since it is smaller than the sum of its proper divisors (1840040480).

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

1211312320 is a wasteful number, since it uses less digits than its factorization.

1211312320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1026 (or 1016 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 1211312320 is about 34803.9124237491. The cubic root of 1211312320 is about 1065.9873348044.

Adding to 1211312320 its reverse (232131121), we get a palindrome (1443443441).

The spelling of 1211312320 in words is "one billion, two hundred eleven million, three hundred twelve thousand, three hundred twenty".