3121213440 has 208 divisors, whose sum is σ = 10264043808. Its totient is φ = 809238528.

The previous prime is 3121213411. The next prime is 3121213483. The reversal of 3121213440 is 443121213.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2272594 + ... + 2273966.

Almost surely, 2^3121213440 is an apocalyptic number.

3121213440 is a gapful number since it is divisible by the number (30) 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 3121213440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5132021904).

3121213440 is an abundant number, since it is smaller than the sum of its proper divisors (7142830368).

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

3121213440 is a wasteful number, since it uses less digits than its factorization.

3121213440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1442 (or 1420 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 3121213440 is about 55867.8211495669. The cubic root of 3121213440 is about 1461.4181254486.

Adding to 3121213440 its reverse (443121213), we get a palindrome (3564334653).

The spelling of 3121213440 in words is "three billion, one hundred twenty-one million, two hundred thirteen thousand, four hundred forty".