21471199 has 2 divisors, whose sum is σ = 21471200. Its totient is φ = 21471198.

The previous prime is 21471193. The next prime is 21471209. The reversal of 21471199 is 99117412.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21471199 is a prime.

It is a super-2 number, since 2×21471199² = 922024772995202, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21471193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10735599 + 10735600.

It is an arithmetic number, because the mean of its divisors is an integer number (10735600).

Almost surely, 2^21471199 is an apocalyptic number.

21471199 is a deficient number, since it is larger than the sum of its proper divisors (1).

21471199 is an equidigital number, since it uses as much as digits as its factorization.

21471199 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4536, while the sum is 34.

The square root of 21471199 is about 4633.7025152679. The cubic root of 21471199 is about 277.9406693254.

The spelling of 21471199 in words is "twenty-one million, four hundred seventy-one thousand, one hundred ninety-nine".