1231111420 has 192 divisors, whose sum is σ = 3351269376. Its totient is φ = 368824320.

The previous prime is 1231111391. The next prime is 1231111433. The reversal of 1231111420 is 241111321.

It is a junction number, because it is equal to n+sod(n) for n = 1231111394 and 1231111403.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5283624 + ... + 5283856.

It is an arithmetic number, because the mean of its divisors is an integer number (17454528).

Almost surely, 2^1231111420 is an apocalyptic number.

1231111420 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 1231111420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1675634688).

1231111420 is an abundant number, since it is smaller than the sum of its proper divisors (2120157956).

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

1231111420 is a wasteful number, since it uses less digits than its factorization.

1231111420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 380 (or 378 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 16.

The square root of 1231111420 is about 35087.1973802411. The cubic root of 1231111420 is about 1071.7638883258.

Adding to 1231111420 its reverse (241111321), we get a palindrome (1472222741).

Subtracting from 1231111420 its reverse (241111321), we obtain a palindrome (990000099).

The spelling of 1231111420 in words is "one billion, two hundred thirty-one million, one hundred eleven thousand, four hundred twenty".