1231122261 has 16 divisors (see below), whose sum is σ = 1671045120. Its totient is φ = 806002800.

The previous prime is 1231122247. The next prime is 1231122283. The reversal of 1231122261 is 1622211321.

It is not a de Polignac number, because 1231122261 - 2⁶ = 1231122197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231122661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 200706 + ... + 206748.

It is an arithmetic number, because the mean of its divisors is an integer number (104440320).

Almost surely, 2^1231122261 is an apocalyptic number.

It is an amenable number.

1231122261 is a deficient number, since it is larger than the sum of its proper divisors (439922859).

1231122261 is a wasteful number, since it uses less digits than its factorization.

1231122261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7256.

The product of its digits is 288, while the sum is 21.

The square root of 1231122261 is about 35087.3518664490. The cubic root of 1231122261 is about 1071.7670342523.

Adding to 1231122261 its reverse (1622211321), we get a palindrome (2853333582).

The spelling of 1231122261 in words is "one billion, two hundred thirty-one million, one hundred twenty-two thousand, two hundred sixty-one".