21470149 has 2 divisors, whose sum is σ = 21470150. Its totient is φ = 21470148.

The previous prime is 21470123. The next prime is 21470219. The reversal of 21470149 is 94107412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21390625 + 79524 = 4625^2 + 282^2 .

It is a cyclic number.

It is not a de Polignac number, because 21470149 - 2¹¹ = 21468101 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is equal to p_1357840 and since 21470149 and 1357840 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21477149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10735074 + 10735075.

It is an arithmetic number, because the mean of its divisors is an integer number (10735075).

Almost surely, 2^21470149 is an apocalyptic number.

It is an amenable number.

21470149 is a deficient number, since it is larger than the sum of its proper divisors (1).

21470149 is an equidigital number, since it uses as much as digits as its factorization.

21470149 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 21470149 is about 4633.5892135579. The cubic root of 21470149 is about 277.9361385667.

The spelling of 21470149 in words is "twenty-one million, four hundred seventy thousand, one hundred forty-nine".