21200401 has 2 divisors, whose sum is σ = 21200402. Its totient is φ = 21200400.

The previous prime is 21200383. The next prime is 21200461. The reversal of 21200401 is 10400212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21160000 + 40401 = 4600^2 + 201^2 .

It is a cyclic number.

It is not a de Polignac number, because 21200401 - 2⁵ = 21200369 is a prime.

It is not a weakly prime, because it can be changed into another prime (21200461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600200 + 10600201.

It is an arithmetic number, because the mean of its divisors is an integer number (10600201).

Almost surely, 2^21200401 is an apocalyptic number.

It is an amenable number.

21200401 is a deficient number, since it is larger than the sum of its proper divisors (1).

21200401 is an equidigital number, since it uses as much as digits as its factorization.

21200401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 21200401 is about 4604.3893189000. The cubic root of 21200401 is about 276.7672457331.

Adding to 21200401 its reverse (10400212), we get a palindrome (31600613).

The spelling of 21200401 in words is "twenty-one million, two hundred thousand, four hundred one".