21440246 has 32 divisors (see below), whose sum is σ = 35164800. Its totient is φ = 9771840.

The previous prime is 21440239. The next prime is 21440257. The reversal of 21440246 is 64204412.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 163601 + ... + 163731.

It is an arithmetic number, because the mean of its divisors is an integer number (1098900).

Almost surely, 2^21440246 is an apocalyptic number.

21440246 is a deficient number, since it is larger than the sum of its proper divisors (13724554).

21440246 is a wasteful number, since it uses less digits than its factorization.

21440246 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284.

The product of its (nonzero) digits is 1536, while the sum is 23.

The square root of 21440246 is about 4630.3613249940. The cubic root of 21440246 is about 277.8070448215.

Adding to 21440246 its reverse (64204412), we get a palindrome (85644658).

The spelling of 21440246 in words is "twenty-one million, four hundred forty thousand, two hundred forty-six".