21973659 has 8 divisors (see below), whose sum is σ = 29321232. Its totient is φ = 14637600.

The previous prime is 21973649. The next prime is 21973681. The reversal of 21973659 is 95637912.

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

It is a de Polignac number, because none of the positive numbers 2^k-21973659 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21973659.

It is not an unprimeable number, because it can be changed into a prime (21973649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3777 + ... + 7629.

It is an arithmetic number, because the mean of its divisors is an integer number (3665154).

Almost surely, 2^21973659 is an apocalyptic number.

21973659 is a deficient number, since it is larger than the sum of its proper divisors (7347573).

21973659 is a wasteful number, since it uses less digits than its factorization.

21973659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5757.

The product of its digits is 102060, while the sum is 42.

The square root of 21973659 is about 4687.6069587797. The cubic root of 21973659 is about 280.0920573155.

The spelling of 21973659 in words is "twenty-one million, nine hundred seventy-three thousand, six hundred fifty-nine".