1231663261 has 8 divisors (see below), whose sum is σ = 1256295584. Its totient is φ = 1207174320.

The previous prime is 1231663259. The next prime is 1231663313. The reversal of 1231663261 is 1623661321.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1231663261 - 2¹ = 1231663259 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231663561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18411 + ... + 52936.

It is an arithmetic number, because the mean of its divisors is an integer number (157036948).

Almost surely, 2^1231663261 is an apocalyptic number.

It is an amenable number.

1231663261 is a deficient number, since it is larger than the sum of its proper divisors (24632323).

1231663261 is an equidigital number, since it uses as much as digits as its factorization.

1231663261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71691.

The product of its digits is 7776, while the sum is 31.

The square root of 1231663261 is about 35095.0603504254. The cubic root of 1231663261 is about 1071.9240024301.

The spelling of 1231663261 in words is "one billion, two hundred thirty-one million, six hundred sixty-three thousand, two hundred sixty-one".