1231067661 has 16 divisors (see below), whose sum is σ = 1699704000. Its totient is φ = 791627648.

The previous prime is 1231067647. The next prime is 1231067711. The reversal of 1231067661 is 1667601321.

It is a cyclic number.

It is not a de Polignac number, because 1231067661 - 2⁷ = 1231067533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231067611) 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, 88990 + ... + 101888.

It is an arithmetic number, because the mean of its divisors is an integer number (106231500).

Almost surely, 2^1231067661 is an apocalyptic number.

It is an amenable number.

1231067661 is a deficient number, since it is larger than the sum of its proper divisors (468636339).

1231067661 is a wasteful number, since it uses less digits than its factorization.

1231067661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14028.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 1231067661 is about 35086.5737996744. The cubic root of 1231067661 is about 1071.7511898077.

Adding to 1231067661 its reverse (1667601321), we get a palindrome (2898668982).

The spelling of 1231067661 in words is "one billion, two hundred thirty-one million, sixty-seven thousand, six hundred sixty-one".