21420201 has 32 divisors (see below), whose sum is σ = 33177600. Its totient is φ = 12156480.

The previous prime is 21420169. The next prime is 21420209. The reversal of 21420201 is 10202412.

It is not a de Polignac number, because 21420201 - 2⁵ = 21420169 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21420209) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 79495 + ... + 79763.

It is an arithmetic number, because the mean of its divisors is an integer number (1036800).

Almost surely, 2^21420201 is an apocalyptic number.

It is an amenable number.

21420201 is a deficient number, since it is larger than the sum of its proper divisors (11757399).

21420201 is a wasteful number, since it uses less digits than its factorization.

21420201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429.

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 21420201 is about 4628.1963009363. The cubic root of 21420201 is about 277.7204416713.

Adding to 21420201 its reverse (10202412), we get a palindrome (31622613).

The spelling of 21420201 in words is "twenty-one million, four hundred twenty thousand, two hundred one".