1231022540 has 144 divisors (see below), whose sum is σ = 3068724960. Its totient is φ = 413107200.

The previous prime is 1231022539. The next prime is 1231022561. The reversal of 1231022540 is 452201321.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1884854 + ... + 1885506.

It is an arithmetic number, because the mean of its divisors is an integer number (21310590).

Almost surely, 2^1231022540 is an apocalyptic number.

1231022540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1231022540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1534362480).

1231022540 is an abundant number, since it is smaller than the sum of its proper divisors (1837702420).

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

1231022540 is a wasteful number, since it uses less digits than its factorization.

1231022540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 744 (or 731 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 1231022540 is about 35085.9307985409. The cubic root of 1231022540 is about 1071.7380957329.

Adding to 1231022540 its reverse (452201321), we get a palindrome (1683223861).

The spelling of 1231022540 in words is "one billion, two hundred thirty-one million, twenty-two thousand, five hundred forty".