1231220011 has 12 divisors (see below), whose sum is σ = 1441031592. Its totient is φ = 1048850208.

The previous prime is 1231219967. The next prime is 1231220033. The reversal of 1231220011 is 1100221321.

It is not a de Polignac number, because 1231220011 - 2¹¹ = 1231217963 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1231219973 and 1231220000.

It is not an unprimeable number, because it can be changed into a prime (1231224011) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 69090 + ... + 85063.

It is an arithmetic number, because the mean of its divisors is an integer number (120085966).

Almost surely, 2^1231220011 is an apocalyptic number.

1231220011 is a deficient number, since it is larger than the sum of its proper divisors (209811581).

1231220011 is a wasteful number, since it uses less digits than its factorization.

1231220011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154330 (or 154323 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1231220011 is about 35088.7447908870. The cubic root of 1231220011 is about 1071.7953992810.

Adding to 1231220011 its reverse (1100221321), we get a palindrome (2331441332).

It can be divided in two parts, 12312 and 20011, that added together give a palindrome (32323).

The spelling of 1231220011 in words is "one billion, two hundred thirty-one million, two hundred twenty thousand, eleven".