21650290 has 8 divisors (see below), whose sum is σ = 38970540. Its totient is φ = 8660112.

The previous prime is 21650287. The next prime is 21650297. The reversal of 21650290 is 9205612.

It can be written as a sum of positive squares in 2 ways, for example, as 18326961 + 3323329 = 4281^2 + 1823^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21650297) 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 3 ways as a sum of consecutive naturals, for example, 1082505 + ... + 1082524.

Almost surely, 2^21650290 is an apocalyptic number.

21650290 is a deficient number, since it is larger than the sum of its proper divisors (17320250).

21650290 is a wasteful number, since it uses less digits than its factorization.

21650290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2165036.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 21650290 is about 4652.9872125335. The cubic root of 21650290 is about 278.7112972200.

The spelling of 21650290 in words is "twenty-one million, six hundred fifty thousand, two hundred ninety".