21472849 has 2 divisors, whose sum is σ = 21472850. Its totient is φ = 21472848.

The previous prime is 21472817. The next prime is 21472879. The reversal of 21472849 is 94827412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17372224 + 4100625 = 4168^2 + 2025^2 .

It is a cyclic number.

It is not a de Polignac number, because 21472849 - 2⁵ = 21472817 is a prime.

It is a super-2 number, since 2×21472849² = 922166488353602, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21472879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10736424 + 10736425.

It is an arithmetic number, because the mean of its divisors is an integer number (10736425).

Almost surely, 2^21472849 is an apocalyptic number.

It is an amenable number.

21472849 is a deficient number, since it is larger than the sum of its proper divisors (1).

21472849 is an equidigital number, since it uses as much as digits as its factorization.

21472849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32256, while the sum is 37.

The square root of 21472849 is about 4633.8805552150. The cubic root of 21472849 is about 277.9477887905.

The spelling of 21472849 in words is "twenty-one million, four hundred seventy-two thousand, eight hundred forty-nine".