21401299 has 2 divisors, whose sum is σ = 21401300. Its totient is φ = 21401298.

The previous prime is 21401291. The next prime is 21401321. The reversal of 21401299 is 99210412.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21401299 - 2³ = 21401291 is a prime.

It is not a weakly prime, because it can be changed into another prime (21401291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10700649 + 10700650.

It is an arithmetic number, because the mean of its divisors is an integer number (10700650).

Almost surely, 2^21401299 is an apocalyptic number.

21401299 is a deficient number, since it is larger than the sum of its proper divisors (1).

21401299 is an equidigital number, since it uses as much as digits as its factorization.

21401299 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 21401299 is about 4626.1538020260. The cubic root of 21401299 is about 277.6387272706.

The spelling of 21401299 in words is "twenty-one million, four hundred one thousand, two hundred ninety-nine".