21010539 has 16 divisors (see below), whose sum is σ = 30637440. Its totient is φ = 12701760.

The previous prime is 21010519. The next prime is 21010543. The reversal of 21010539 is 93501012.

It is not a de Polignac number, because 21010539 - 2⁷ = 21010411 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21010519) 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, 25567 + ... + 26375.

It is an arithmetic number, because the mean of its divisors is an integer number (1914840).

Almost surely, 2^21010539 is an apocalyptic number.

21010539 is a deficient number, since it is larger than the sum of its proper divisors (9626901).

21010539 is a wasteful number, since it uses less digits than its factorization.

21010539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1610.

The product of its (nonzero) digits is 270, while the sum is 21.

The square root of 21010539 is about 4583.7254498934. The cubic root of 21010539 is about 275.9385627797.

The spelling of 21010539 in words is "twenty-one million, ten thousand, five hundred thirty-nine".