21499005 has 32 divisors (see below), whose sum is σ = 38828160. Its totient is φ = 10062080.

The previous prime is 21499003. The next prime is 21499021. The reversal of 21499005 is 50099412.

It is a happy number.

It is not a de Polignac number, because 21499005 - 2¹ = 21499003 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21499003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2539 + ... + 7031.

It is an arithmetic number, because the mean of its divisors is an integer number (1213380).

Almost surely, 2^21499005 is an apocalyptic number.

It is an amenable number.

21499005 is a deficient number, since it is larger than the sum of its proper divisors (17329155).

21499005 is a wasteful number, since it uses less digits than its factorization.

21499005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4541.

The product of its (nonzero) digits is 3240, while the sum is 30.

The square root of 21499005 is about 4636.7019528971. The cubic root of 21499005 is about 278.0605987318.

The spelling of 21499005 in words is "twenty-one million, four hundred ninety-nine thousand, five".