21616953 has 8 divisors (see below), whose sum is σ = 28860768. Its totient is φ = 14392224.

The previous prime is 21616949. The next prime is 21616957. The reversal of 21616953 is 35961612.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21616949) and next prime (21616957).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21616953 - 2² = 21616949 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21616957) 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, 1876 + ... + 6837.

It is an arithmetic number, because the mean of its divisors is an integer number (3607596).

Almost surely, 2^21616953 is an apocalyptic number.

It is an amenable number.

21616953 is a deficient number, since it is larger than the sum of its proper divisors (7243815).

21616953 is an equidigital number, since it uses as much as digits as its factorization.

21616953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9543.

The product of its digits is 9720, while the sum is 33.

The square root of 21616953 is about 4649.4035101290. The cubic root of 21616953 is about 278.5681710148.

The spelling of 21616953 in words is "twenty-one million, six hundred sixteen thousand, nine hundred fifty-three".