21959371 has 8 divisors (see below), whose sum is σ = 25159680. Its totient is φ = 18774888.

The previous prime is 21959341. The next prime is 21959407. The reversal of 21959371 is 17395912.

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 21959371 - 2⁵ = 21959339 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21959371.

It is not an unprimeable number, because it can be changed into a prime (21959341) 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, 811 + ... + 6676.

It is an arithmetic number, because the mean of its divisors is an integer number (3144960).

Almost surely, 2^21959371 is an apocalyptic number.

21959371 is a deficient number, since it is larger than the sum of its proper divisors (3200309).

21959371 is an equidigital number, since it uses as much as digits as its factorization.

21959371 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7913.

The product of its digits is 17010, while the sum is 37.

The square root of 21959371 is about 4686.0826923988. The cubic root of 21959371 is about 280.0313357787.

The spelling of 21959371 in words is "twenty-one million, nine hundred fifty-nine thousand, three hundred seventy-one".