21996619 has 4 divisors (see below), whose sum is σ = 22023144. Its totient is φ = 21970096.

The previous prime is 21996613. The next prime is 21996629. The reversal of 21996619 is 91669912.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21996619 is a prime.

It is a super-2 number, since 2×21996619² = 967702494862322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21996613) 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 3 ways as a sum of consecutive naturals, for example, 11977 + ... + 13690.

It is an arithmetic number, because the mean of its divisors is an integer number (5505786).

Almost surely, 2^21996619 is an apocalyptic number.

21996619 is a deficient number, since it is larger than the sum of its proper divisors (26525).

21996619 is an equidigital number, since it uses as much as digits as its factorization.

21996619 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26524.

The product of its digits is 52488, while the sum is 43.

The square root of 21996619 is about 4690.0553301640. The cubic root of 21996619 is about 280.1895782469.

The spelling of 21996619 in words is "twenty-one million, nine hundred ninety-six thousand, six hundred nineteen".