21298039 has 4 divisors (see below), whose sum is σ = 24340624. Its totient is φ = 18255456.

The previous prime is 21298033. The next prime is 21298073. The reversal of 21298039 is 93089212.

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 21298039 - 2²³ = 12909431 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21297995 and 21298013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21298033) 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, 1521282 + ... + 1521295.

It is an arithmetic number, because the mean of its divisors is an integer number (6085156).

Almost surely, 2^21298039 is an apocalyptic number.

21298039 is a deficient number, since it is larger than the sum of its proper divisors (3042585).

21298039 is an equidigital number, since it uses as much as digits as its factorization.

21298039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3042584.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 21298039 is about 4614.9798482767. The cubic root of 21298039 is about 277.1914770410.

The spelling of 21298039 in words is "twenty-one million, two hundred ninety-eight thousand, thirty-nine".