1231220431 has 8 divisors (see below), whose sum is σ = 1420260480. Its totient is φ = 1045468248.

The previous prime is 1231220381. The next prime is 1231220453. The reversal of 1231220431 is 1340221321.

It is a happy number.

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 1231220431 - 2⁷ = 1231220303 is a prime.

It is a super-5 number, since 5×1231220431⁵ (a number of 47 digits) contains 55555 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1231220399 and 1231220408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231220531) 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, 821161 + ... + 822658.

It is an arithmetic number, because the mean of its divisors is an integer number (177532560).

Almost surely, 2^1231220431 is an apocalyptic number.

1231220431 is a deficient number, since it is larger than the sum of its proper divisors (189040049).

1231220431 is a wasteful number, since it uses less digits than its factorization.

1231220431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1643933.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 1231220431 is about 35088.7507757116. The cubic root of 1231220431 is about 1071.7955211531.

Adding to 1231220431 its reverse (1340221321), we get a palindrome (2571441752).

The spelling of 1231220431 in words is "one billion, two hundred thirty-one million, two hundred twenty thousand, four hundred thirty-one".