21349445 has 32 divisors (see below), whose sum is σ = 29635200. Its totient is φ = 14632704.

The previous prime is 21349403. The next prime is 21349453. The reversal of 21349445 is 54494312.

It is a cyclic number.

It is not a de Polignac number, because 21349445 - 2⁸ = 21349189 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 72719 + ... + 73011.

It is an arithmetic number, because the mean of its divisors is an integer number (926100).

Almost surely, 2^21349445 is an apocalyptic number.

It is an amenable number.

21349445 is a deficient number, since it is larger than the sum of its proper divisors (8285755).

21349445 is a wasteful number, since it uses less digits than its factorization.

21349445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389.

The product of its digits is 17280, while the sum is 32.

The square root of 21349445 is about 4620.5459634117. The cubic root of 21349445 is about 277.4143122066.

The spelling of 21349445 in words is "twenty-one million, three hundred forty-nine thousand, four hundred forty-five".