21475151 has 2 divisors, whose sum is σ = 21475152. Its totient is φ = 21475150.

The previous prime is 21475147. The next prime is 21475159. The reversal of 21475151 is 15157412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21475151 - 2² = 21475147 is a prime.

It is a super-2 number, since 2×21475151² = 922364220945602, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21475151.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21475159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10737575 + 10737576.

It is an arithmetic number, because the mean of its divisors is an integer number (10737576).

Almost surely, 2^21475151 is an apocalyptic number.

21475151 is a deficient number, since it is larger than the sum of its proper divisors (1).

21475151 is an equidigital number, since it uses as much as digits as its factorization.

21475151 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1400, while the sum is 26.

The square root of 21475151 is about 4634.1289364885. The cubic root of 21475151 is about 277.9577209137.

The spelling of 21475151 in words is "twenty-one million, four hundred seventy-five thousand, one hundred fifty-one".