21329401 has 2 divisors, whose sum is σ = 21329402. Its totient is φ = 21329400.

The previous prime is 21329377. The next prime is 21329431. The reversal of 21329401 is 10492312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20475625 + 853776 = 4525^2 + 924^2 .

It is a cyclic number.

It is not a de Polignac number, because 21329401 - 2¹¹ = 21327353 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21329431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10664700 + 10664701.

It is an arithmetic number, because the mean of its divisors is an integer number (10664701).

Almost surely, 2^21329401 is an apocalyptic number.

It is an amenable number.

21329401 is a deficient number, since it is larger than the sum of its proper divisors (1).

21329401 is an equidigital number, since it uses as much as digits as its factorization.

21329401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 21329401 is about 4618.3764463283. The cubic root of 21329401 is about 277.3274678953.

The spelling of 21329401 in words is "twenty-one million, three hundred twenty-nine thousand, four hundred one".