21400151 has 2 divisors, whose sum is σ = 21400152. Its totient is φ = 21400150.

The previous prime is 21400121. The next prime is 21400153. The reversal of 21400151 is 15100412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21400151 - 2¹⁰ = 21399127 is a prime.

Together with 21400153, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21400153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10700075 + 10700076.

It is an arithmetic number, because the mean of its divisors is an integer number (10700076).

Almost surely, 2^21400151 is an apocalyptic number.

21400151 is a deficient number, since it is larger than the sum of its proper divisors (1).

21400151 is an equidigital number, since it uses as much as digits as its factorization.

21400151 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 21400151 is about 4626.0297232076. The cubic root of 21400151 is about 277.6337628530.

Adding to 21400151 its reverse (15100412), we get a palindrome (36500563).

The spelling of 21400151 in words is "twenty-one million, four hundred thousand, one hundred fifty-one".