21000411650 has 24 divisors (see below), whose sum is σ = 39079891584. Its totient is φ = 8396051600.

The previous prime is 21000411647. The next prime is 21000411659. The reversal of 21000411650 is 5611400012.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21000411659) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1355 + ... + 204945.

It is an arithmetic number, because the mean of its divisors is an integer number (1628328816).

Almost surely, 2^21000411650 is an apocalyptic number.

21000411650 is a deficient number, since it is larger than the sum of its proper divisors (18079479934).

21000411650 is a wasteful number, since it uses less digits than its factorization.

21000411650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205666 (or 205661 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

Adding to 21000411650 its reverse (5611400012), we get a palindrome (26611811662).

The spelling of 21000411650 in words is "twenty-one billion, four hundred eleven thousand, six hundred fifty".