21383989 has 8 divisors (see below), whose sum is σ = 23395968. Its totient is φ = 19383360.

The previous prime is 21383969. The next prime is 21384061. The reversal of 21383989 is 98938312.

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 21383989 - 2¹³ = 21375797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21383969) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1389 + ... + 6685.

It is an arithmetic number, because the mean of its divisors is an integer number (2924496).

Almost surely, 2^21383989 is an apocalyptic number.

It is an amenable number.

21383989 is a deficient number, since it is larger than the sum of its proper divisors (2011979).

21383989 is a wasteful number, since it uses less digits than its factorization.

21383989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5675.

The product of its digits is 93312, while the sum is 43.

The square root of 21383989 is about 4624.2825389459. The cubic root of 21383989 is about 277.5638529577.

The spelling of 21383989 in words is "twenty-one million, three hundred eighty-three thousand, nine hundred eighty-nine".