21894413 has 8 divisors (see below), whose sum is σ = 22907328. Its totient is φ = 20886624.

The previous prime is 21894409. The next prime is 21894421. The reversal of 21894413 is 31449812.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21894413 - 2² = 21894409 is a prime.

It is a super-2 number, since 2×21894413² = 958730641229138, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21894413.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21894443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9470 + ... + 11552.

It is an arithmetic number, because the mean of its divisors is an integer number (2863416).

Almost surely, 2^21894413 is an apocalyptic number.

21894413 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21894413 is a deficient number, since it is larger than the sum of its proper divisors (1012915).

21894413 is a wasteful number, since it uses less digits than its factorization.

21894413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2563.

The product of its digits is 6912, while the sum is 32.

The square root of 21894413 is about 4679.1466102271. The cubic root of 21894413 is about 279.7549429006.

The spelling of 21894413 in words is "twenty-one million, eight hundred ninety-four thousand, four hundred thirteen".