21682653 has 4 divisors (see below), whose sum is σ = 28910208. Its totient is φ = 14455100.

The previous prime is 21682643. The next prime is 21682657. The reversal of 21682653 is 35628612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21682653 - 2⁶ = 21682589 is a prime.

It is a super-2 number, since 2×21682653² = 940274882236818, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21682657) 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, 3613773 + ... + 3613778.

It is an arithmetic number, because the mean of its divisors is an integer number (7227552).

Almost surely, 2^21682653 is an apocalyptic number.

It is an amenable number.

21682653 is a deficient number, since it is larger than the sum of its proper divisors (7227555).

21682653 is an equidigital number, since it uses as much as digits as its factorization.

21682653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7227554.

The product of its digits is 17280, while the sum is 33.

The square root of 21682653 is about 4656.4635722832. The cubic root of 21682653 is about 278.8501012589.

The spelling of 21682653 in words is "twenty-one million, six hundred eighty-two thousand, six hundred fifty-three".