21207419 has 4 divisors (see below), whose sum is σ = 21317496. Its totient is φ = 21097344.

The previous prime is 21207377. The next prime is 21207421. The reversal of 21207419 is 91470212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21207419 - 2²⁰ = 20158843 is a prime.

It is a super-2 number, since 2×21207419² = 899509241283122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21207469) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54749 + ... + 55134.

It is an arithmetic number, because the mean of its divisors is an integer number (5329374).

Almost surely, 2^21207419 is an apocalyptic number.

21207419 is a deficient number, since it is larger than the sum of its proper divisors (110077).

21207419 is a wasteful number, since it uses less digits than its factorization.

21207419 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110076.

The product of its (nonzero) digits is 1008, while the sum is 26.

The square root of 21207419 is about 4605.1513547331. The cubic root of 21207419 is about 276.7977819203.

The spelling of 21207419 in words is "twenty-one million, two hundred seven thousand, four hundred nineteen".