1211320231 has 12 divisors (see below), whose sum is σ = 1389343536. Its totient is φ = 1053319520.

The previous prime is 1211320217. The next prime is 1211320241. The reversal of 1211320231 is 1320231121.

It is not a de Polignac number, because 1211320231 - 2⁵ = 1211320199 is a prime.

It is a super-2 number, since 2×1211320231² = 2934593404059786722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211320241) 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, 214846 + ... + 220411.

It is an arithmetic number, because the mean of its divisors is an integer number (115778628).

Almost surely, 2^1211320231 is an apocalyptic number.

1211320231 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1211320231 is a deficient number, since it is larger than the sum of its proper divisors (178023305).

1211320231 is a wasteful number, since it uses less digits than its factorization.

1211320231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 435302 (or 435291 counting only the distinct ones).

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

The square root of 1211320231 is about 34804.0260745794. The cubic root of 1211320231 is about 1065.9896554301.

Adding to 1211320231 its reverse (1320231121), we get a palindrome (2531551352).

It can be divided in two parts, 121 and 1320231, that multiplied together give a palindrome (159747951).

The spelling of 1211320231 in words is "one billion, two hundred eleven million, three hundred twenty thousand, two hundred thirty-one".