21425201 has 12 divisors (see below), whose sum is σ = 25349040. Its totient is φ = 18050760.

The previous prime is 21425189. The next prime is 21425203. The reversal of 21425201 is 10252412.

It is not a de Polignac number, because 21425201 - 2¹⁸ = 21163057 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21425201.

It is not an unprimeable number, because it can be changed into a prime (21425203) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 815 + ... + 6596.

It is an arithmetic number, because the mean of its divisors is an integer number (2112420).

Almost surely, 2^21425201 is an apocalyptic number.

It is an amenable number.

21425201 is a deficient number, since it is larger than the sum of its proper divisors (3923839).

21425201 is an equidigital number, since it uses as much as digits as its factorization.

21425201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7484 (or 7477 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 21425201 is about 4628.7364366531. The cubic root of 21425201 is about 277.7420489098.

Adding to 21425201 its reverse (10252412), we get a palindrome (31677613).

The spelling of 21425201 in words is "twenty-one million, four hundred twenty-five thousand, two hundred one".