21471019 has 2 divisors, whose sum is σ = 21471020. Its totient is φ = 21471018.

The previous prime is 21470987. The next prime is 21471041. The reversal of 21471019 is 91017412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21471019 - 2⁵ = 21470987 is a prime.

It is a super-2 number, since 2×21471019² = 922009313796722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21470984 and 21471002.

It is not a weakly prime, because it can be changed into another prime (21471089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10735509 + 10735510.

It is an arithmetic number, because the mean of its divisors is an integer number (10735510).

Almost surely, 2^21471019 is an apocalyptic number.

21471019 is a deficient number, since it is larger than the sum of its proper divisors (1).

21471019 is an equidigital number, since it uses as much as digits as its factorization.

21471019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 504, while the sum is 25.

The square root of 21471019 is about 4633.6830923144. The cubic root of 21471019 is about 277.9398926344.

The spelling of 21471019 in words is "twenty-one million, four hundred seventy-one thousand, nineteen".