21797039 has 8 divisors (see below), whose sum is σ = 23880960. Its totient is φ = 19730200.

The previous prime is 21797023. The next prime is 21797053. The reversal of 21797039 is 93079712.

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 21797039 - 2⁴ = 21797023 is a prime.

It is a super-2 number, since 2×21797039² = 950221818335042, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21796993 and 21797011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21797939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1517 + ... + 6774.

It is an arithmetic number, because the mean of its divisors is an integer number (2985120).

Almost surely, 2^21797039 is an apocalyptic number.

21797039 is a deficient number, since it is larger than the sum of its proper divisors (2083921).

21797039 is a wasteful number, since it uses less digits than its factorization.

21797039 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8541.

The product of its (nonzero) digits is 23814, while the sum is 38.

The square root of 21797039 is about 4668.7299129421. The cubic root of 21797039 is about 279.3395958152.

It can be divided in two parts, 2179703 and 9, that added together give a palindrome (2179712).

The spelling of 21797039 in words is "twenty-one million, seven hundred ninety-seven thousand, thirty-nine".