1231601220 has 96 divisors (see below), whose sum is σ = 3857616000. Its totient is φ = 326201472.

The previous prime is 1231601219. The next prime is 1231601237. The reversal of 1231601220 is 221061321.

1231601220 is a `hidden beast` number, since 12 + 31 + 601 + 2 + 20 = 666.

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 = 1231601193 and 1231601202.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 72807 + ... + 88113.

It is an arithmetic number, because the mean of its divisors is an integer number (40183500).

Almost surely, 2^1231601220 is an apocalyptic number.

1231601220 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 1231601220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1928808000).

1231601220 is an abundant number, since it is smaller than the sum of its proper divisors (2626014780).

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

1231601220 is a wasteful number, since it uses less digits than its factorization.

1231601220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15474 (or 15466 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 1231601220 is about 35094.1764399736. The cubic root of 1231601220 is about 1071.9060039085.

Adding to 1231601220 its reverse (221061321), we get a palindrome (1452662541).

The spelling of 1231601220 in words is "one billion, two hundred thirty-one million, six hundred one thousand, two hundred twenty".