21269401 has 2 divisors, whose sum is σ = 21269402. Its totient is φ = 21269400.

The previous prime is 21269359. The next prime is 21269449. The reversal of 21269401 is 10496212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15217801 + 6051600 = 3901^2 + 2460^2 .

It is a cyclic number.

It is not a de Polignac number, because 21269401 - 2⁹ = 21268889 is a prime.

It is not a weakly prime, because it can be changed into another prime (21269471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10634700 + 10634701.

It is an arithmetic number, because the mean of its divisors is an integer number (10634701).

Almost surely, 2^21269401 is an apocalyptic number.

It is an amenable number.

21269401 is a deficient number, since it is larger than the sum of its proper divisors (1).

21269401 is an equidigital number, since it uses as much as digits as its factorization.

21269401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 21269401 is about 4611.8760824636. The cubic root of 21269401 is about 277.0671812445.

The spelling of 21269401 in words is "twenty-one million, two hundred sixty-nine thousand, four hundred one".