10021540 has 12 divisors (see below), whose sum is σ = 21045276. Its totient is φ = 4008608.

The previous prime is 10021519. The next prime is 10021541. The reversal of 10021540 is 4512001.

It can be written as a sum of positive squares in 2 ways, for example, as 2742336 + 7279204 = 1656^2 + 2698^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 10021540.

It is not an unprimeable number, because it can be changed into a prime (10021541) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 250519 + ... + 250558.

It is an arithmetic number, because the mean of its divisors is an integer number (1753773).

Almost surely, 2^10021540 is an apocalyptic number.

10021540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

10021540 is an abundant number, since it is smaller than the sum of its proper divisors (11023736).

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

10021540 is a wasteful number, since it uses less digits than its factorization.

10021540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 501086 (or 501084 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 10021540 is about 3165.6816011722. The cubic root of 10021540 is about 215.5980464804.

Adding to 10021540 its reverse (4512001), we get a palindrome (14533541).

The spelling of 10021540 in words is "ten million, twenty-one thousand, five hundred forty".