21464249 has 2 divisors, whose sum is σ = 21464250. Its totient is φ = 21464248.

The previous prime is 21464239. The next prime is 21464269. The reversal of 21464249 is 94246412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11854249 + 9610000 = 3443^2 + 3100^2 .

It is a cyclic number.

It is not a de Polignac number, because 21464249 - 2²⁰ = 20415673 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21464239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10732124 + 10732125.

It is an arithmetic number, because the mean of its divisors is an integer number (10732125).

Almost surely, 2^21464249 is an apocalyptic number.

It is an amenable number.

21464249 is a deficient number, since it is larger than the sum of its proper divisors (1).

21464249 is an equidigital number, since it uses as much as digits as its factorization.

21464249 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13824, while the sum is 32.

The square root of 21464249 is about 4632.9525143260. The cubic root of 21464249 is about 277.9106772709.

The spelling of 21464249 in words is "twenty-one million, four hundred sixty-four thousand, two hundred forty-nine".