21466401 has 16 divisors (see below), whose sum is σ = 32069568. Its totient is φ = 12657600.

The previous prime is 21466397. The next prime is 21466421. The reversal of 21466401 is 10466412.

It is not a de Polignac number, because 21466401 - 2² = 21466397 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21466421) 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, 7570 + ... + 10011.

It is an arithmetic number, because the mean of its divisors is an integer number (2004348).

Almost surely, 2^21466401 is an apocalyptic number.

It is an amenable number.

21466401 is a deficient number, since it is larger than the sum of its proper divisors (10603167).

21466401 is a wasteful number, since it uses less digits than its factorization.

21466401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17632.

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 21466401 is about 4633.1847578097. The cubic root of 21466401 is about 277.9199647111.

The spelling of 21466401 in words is "twenty-one million, four hundred sixty-six thousand, four hundred one".