21400153 has 2 divisors, whose sum is σ = 21400154. Its totient is φ = 21400152.

The previous prime is 21400151. The next prime is 21400157. The reversal of 21400153 is 35100412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11108889 + 10291264 = 3333^2 + 3208^2 .

It is a cyclic number.

It is not a de Polignac number, because 21400153 - 2¹ = 21400151 is a prime.

Together with 21400151, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21400151) 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, 10700076 + 10700077.

It is an arithmetic number, because the mean of its divisors is an integer number (10700077).

Almost surely, 2^21400153 is an apocalyptic number.

It is an amenable number.

21400153 is a deficient number, since it is larger than the sum of its proper divisors (1).

21400153 is an equidigital number, since it uses as much as digits as its factorization.

21400153 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 21400153 is about 4626.0299393757. The cubic root of 21400153 is about 277.6337715020.

Adding to 21400153 its reverse (35100412), we get a palindrome (56500565).

The spelling of 21400153 in words is "twenty-one million, four hundred thousand, one hundred fifty-three".