21957803 has 8 divisors (see below), whose sum is σ = 25226208. Its totient is φ = 18722304.

The previous prime is 21957799. The next prime is 21957809. The reversal of 21957803 is 30875912.

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 21957803 - 2² = 21957799 is a prime.

It is a super-2 number, since 2×21957803² = 964290225173618, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21957809) 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, 6776 + ... + 9477.

It is an arithmetic number, because the mean of its divisors is an integer number (3153276).

Almost surely, 2^21957803 is an apocalyptic number.

21957803 is a deficient number, since it is larger than the sum of its proper divisors (3268405).

21957803 is a wasteful number, since it uses less digits than its factorization.

21957803 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16453.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 21957803 is about 4685.9153854930. The cubic root of 21957803 is about 280.0246704453.

The spelling of 21957803 in words is "twenty-one million, nine hundred fifty-seven thousand, eight hundred three".