21013502 has 8 divisors (see below), whose sum is σ = 31550256. Its totient is φ = 10496752.

The previous prime is 21013501. The next prime is 21013507. The reversal of 21013502 is 20531012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21013501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2018 + ... + 6789.

It is an arithmetic number, because the mean of its divisors is an integer number (3943782).

Almost surely, 2^21013502 is an apocalyptic number.

21013502 is a deficient number, since it is larger than the sum of its proper divisors (10536754).

21013502 is a wasteful number, since it uses less digits than its factorization.

21013502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10002.

The product of its (nonzero) digits is 60, while the sum is 14.

The square root of 21013502 is about 4584.0486472113. The cubic root of 21013502 is about 275.9515335326.

Adding to 21013502 its reverse (20531012), we get a palindrome (41544514).

The spelling of 21013502 in words is "twenty-one million, thirteen thousand, five hundred two".