21247410 has 32 divisors (see below), whose sum is σ = 51311232. Its totient is φ = 5630720.

The previous prime is 21247393. The next prime is 21247411. The reversal of 21247410 is 1474212.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21247411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2890 + ... + 7130.

It is an arithmetic number, because the mean of its divisors is an integer number (1603476).

Almost surely, 2^21247410 is an apocalyptic number.

21247410 is an abundant number, since it is smaller than the sum of its proper divisors (30063822).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21247410 is a wasteful number, since it uses less digits than its factorization.

21247410 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4418.

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 21247410 is about 4609.4912951431. The cubic root of 21247410 is about 276.9716592708.

The spelling of 21247410 in words is "twenty-one million, two hundred forty-seven thousand, four hundred ten".