21013246 has 4 divisors (see below), whose sum is σ = 31519872. Its totient is φ = 10506622.

The previous prime is 21013217. The next prime is 21013249. The reversal of 21013246 is 64231012.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21013249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5253310 + ... + 5253313.

It is an arithmetic number, because the mean of its divisors is an integer number (7879968).

Almost surely, 2^21013246 is an apocalyptic number.

21013246 is a deficient number, since it is larger than the sum of its proper divisors (10506626).

21013246 is a wasteful number, since it uses less digits than its factorization.

21013246 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10506625.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 21013246 is about 4584.0207242114. The cubic root of 21013246 is about 275.9504129217.

Adding to 21013246 its reverse (64231012), we get a palindrome (85244258).

It can be divided in two parts, 210 and 13246, that added together give a square (13456 = 116²).

The spelling of 21013246 in words is "twenty-one million, thirteen thousand, two hundred forty-six".