5121540 has 72 divisors (see below), whose sum is σ = 15975960. Its totient is φ = 1327104.

The previous prime is 5121533. The next prime is 5121551. The reversal of 5121540 is 451215.

5121540 is a `hidden beast` number, since 5 + 121 + 540 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1153476 + 3968064 = 1074^2 + 1992^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6276 + ... + 7044.

Almost surely, 2^5121540 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 5121540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7987980).

5121540 is an abundant number, since it is smaller than the sum of its proper divisors (10854420).

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

5121540 is a wasteful number, since it uses less digits than its factorization.

5121540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 821 (or 816 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 5121540 is about 2263.0819693506. The cubic root of 5121540 is about 172.3720538319.

Adding to 5121540 its reverse (451215), we get a palindrome (5572755).

The spelling of 5121540 in words is "five million, one hundred twenty-one thousand, five hundred forty".