21125783 has 8 divisors (see below), whose sum is σ = 24732960. Its totient is φ = 17665920.

The previous prime is 21125761. The next prime is 21125789. The reversal of 21125783 is 38752112.

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 21125783 - 2¹⁰ = 21124759 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21125789) 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, 36518 + ... + 37091.

It is an arithmetic number, because the mean of its divisors is an integer number (3091620).

Almost surely, 2^21125783 is an apocalyptic number.

21125783 is a deficient number, since it is larger than the sum of its proper divisors (3607177).

21125783 is an equidigital number, since it uses as much as digits as its factorization.

21125783 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73657.

The product of its digits is 3360, while the sum is 29.

The square root of 21125783 is about 4596.2792560940. The cubic root of 21125783 is about 276.4421560506.

Adding to 21125783 its reverse (38752112), we get a palindrome (59877895).

The spelling of 21125783 in words is "twenty-one million, one hundred twenty-five thousand, seven hundred eighty-three".