21998039 has 8 divisors (see below), whose sum is σ = 25485600. Its totient is φ = 18596736.

The previous prime is 21998033. The next prime is 21998107. The reversal of 21998039 is 93089912.

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 21998039 - 2⁸ = 21997783 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21997987 and 21998005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21998033) 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, 21014 + ... + 22035.

It is an arithmetic number, because the mean of its divisors is an integer number (3185700).

Almost surely, 2^21998039 is an apocalyptic number.

21998039 is a deficient number, since it is larger than the sum of its proper divisors (3487561).

21998039 is an equidigital number, since it uses as much as digits as its factorization.

21998039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43129.

The product of its (nonzero) digits is 34992, while the sum is 41.

The square root of 21998039 is about 4690.2067118625. The cubic root of 21998039 is about 280.1956073649.

The spelling of 21998039 in words is "twenty-one million, nine hundred ninety-eight thousand, thirty-nine".