1231261506 has 64 divisors (see below), whose sum is σ = 2819174400. Its totient is φ = 398037888.

The previous prime is 1231261483. The next prime is 1231261517. The reversal of 1231261506 is 6051621321.

1231261506 is a `hidden beast` number, since 12 + 31 + 2 + 615 + 0 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 1231261506.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 764430 + ... + 766038.

It is an arithmetic number, because the mean of its divisors is an integer number (44049600).

Almost surely, 2^1231261506 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1231261506, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1409587200).

1231261506 is an abundant number, since it is smaller than the sum of its proper divisors (1587912894).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1231261506 is a wasteful number, since it uses less digits than its factorization.

1231261506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2040 (or 2034 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 1231261506 is about 35089.3360723739. The cubic root of 1231261506 is about 1071.8074398181.

Adding to 1231261506 its reverse (6051621321), we get a palindrome (7282882827).

The spelling of 1231261506 in words is "one billion, two hundred thirty-one million, two hundred sixty-one thousand, five hundred six".