21248473 has 2 divisors, whose sum is σ = 21248474. Its totient is φ = 21248472.

The previous prime is 21248431. The next prime is 21248477. The reversal of 21248473 is 37484212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13564489 + 7683984 = 3683^2 + 2772^2 .

It is a cyclic number.

It is not a de Polignac number, because 21248473 - 2¹⁷ = 21117401 is a prime.

It is not a weakly prime, because it can be changed into another prime (21248477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10624236 + 10624237.

It is an arithmetic number, because the mean of its divisors is an integer number (10624237).

Almost surely, 2^21248473 is an apocalyptic number.

It is an amenable number.

21248473 is a deficient number, since it is larger than the sum of its proper divisors (1).

21248473 is an equidigital number, since it uses as much as digits as its factorization.

21248473 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10752, while the sum is 31.

The square root of 21248473 is about 4609.6065992664. The cubic root of 21248473 is about 276.9762781234.

The spelling of 21248473 in words is "twenty-one million, two hundred forty-eight thousand, four hundred seventy-three".