21032445 has 32 divisors (see below), whose sum is σ = 38633472. Its totient is φ = 9571392.

The previous prime is 21032441. The next prime is 21032447. The reversal of 21032445 is 54423012.

It is not a de Polignac number, because 21032445 - 2² = 21032441 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21032441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39954 + ... + 40476.

It is an arithmetic number, because the mean of its divisors is an integer number (1207296).

Almost surely, 2^21032445 is an apocalyptic number.

It is an amenable number.

21032445 is a deficient number, since it is larger than the sum of its proper divisors (17601027).

21032445 is a wasteful number, since it uses less digits than its factorization.

21032445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 921.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 21032445 is about 4586.1143683951. The cubic root of 21032445 is about 276.0344291224.

Adding to 21032445 its reverse (54423012), we get a palindrome (75455457).

The spelling of 21032445 in words is "twenty-one million, thirty-two thousand, four hundred forty-five".