21650145 has 16 divisors (see below), whose sum is σ = 37789632. Its totient is φ = 10496960.

The previous prime is 21650137. The next prime is 21650159. The reversal of 21650145 is 54105612.

It is not a de Polignac number, because 21650145 - 2³ = 21650137 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 65442 + ... + 65771.

It is an arithmetic number, because the mean of its divisors is an integer number (2361852).

Almost surely, 2^21650145 is an apocalyptic number.

It is an amenable number.

21650145 is a deficient number, since it is larger than the sum of its proper divisors (16139487).

21650145 is a wasteful number, since it uses less digits than its factorization.

21650145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131232.

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 21650145 is about 4652.9716311192. The cubic root of 21650145 is about 278.7106750077.

Adding to 21650145 its reverse (54105612), we get a palindrome (75755757).

The spelling of 21650145 in words is "twenty-one million, six hundred fifty thousand, one hundred forty-five".