21001246 has 16 divisors (see below), whose sum is σ = 36226944. Its totient is φ = 8944344.

The previous prime is 21001187. The next prime is 21001247. The reversal of 21001246 is 64210012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001247) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2320 + ... + 6883.

It is an arithmetic number, because the mean of its divisors is an integer number (2264184).

Almost surely, 2^21001246 is an apocalyptic number.

21001246 is a deficient number, since it is larger than the sum of its proper divisors (15225698).

21001246 is a wasteful number, since it uses less digits than its factorization.

21001246 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9375.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 21001246 is about 4582.7116426849. The cubic root of 21001246 is about 275.8978740691.

Adding to 21001246 its reverse (64210012), we get a palindrome (85211258).

The spelling of 21001246 in words is "twenty-one million, one thousand, two hundred forty-six".