1213322440 has 64 divisors (see below), whose sum is σ = 3001743360. Its totient is φ = 437713920.

The previous prime is 1213322431. The next prime is 1213322449. The reversal of 1213322440 is 442233121.

It is an interprime number because it is at equal distance from previous prime (1213322431) and next prime (1213322449).

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (1213322449) 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, 45024 + ... + 66736.

It is an arithmetic number, because the mean of its divisors is an integer number (46902240).

Almost surely, 2^1213322440 is an apocalyptic number.

1213322440 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 1213322440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1500871680).

1213322440 is an abundant number, since it is smaller than the sum of its proper divisors (1788420920).

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

1213322440 is a wasteful number, since it uses less digits than its factorization.

1213322440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21862 (or 21858 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 1213322440 is about 34832.7782411912. The cubic root of 1213322440 is about 1066.5766621106.

Adding to 1213322440 its reverse (442233121), we get a palindrome (1655555561).

The spelling of 1213322440 in words is "one billion, two hundred thirteen million, three hundred twenty-two thousand, four hundred forty".