3121535440 has 40 divisors (see below), whose sum is σ = 7264389960. Its totient is φ = 1247440896.

The previous prime is 3121535423. The next prime is 3121535447. The reversal of 3121535440 is 445351213.

3121535440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 779749776 + 2341785664 = 27924^2 + 48392^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 3121535399 and 3121535408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3121535447) 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, 69976 + ... + 105544.

It is an arithmetic number, because the mean of its divisors is an integer number (181609749).

Almost surely, 2^3121535440 is an apocalyptic number.

It is an amenable number.

3121535440 is an abundant number, since it is smaller than the sum of its proper divisors (4142854520).

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

3121535440 is a wasteful number, since it uses less digits than its factorization.

3121535440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36679 (or 36673 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 28.

The square root of 3121535440 is about 55870.7028772683. The cubic root of 3121535440 is about 1461.4683794565.

Adding to 3121535440 its reverse (445351213), we get a palindrome (3566886653).

The spelling of 3121535440 in words is "three billion, one hundred twenty-one million, five hundred thirty-five thousand, four hundred forty".