21500650 has 12 divisors (see below), whose sum is σ = 39991302. Its totient is φ = 8600240.

The previous prime is 21500641. The next prime is 21500651. The reversal of 21500650 is 5600512.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 11215801 + 10284849 = 3349^2 + 3207^2 .

It is not an unprimeable number, because it can be changed into a prime (21500651) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 214957 + ... + 215056.

Almost surely, 2^21500650 is an apocalyptic number.

21500650 is a deficient number, since it is larger than the sum of its proper divisors (18490652).

21500650 is a wasteful number, since it uses less digits than its factorization.

21500650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430025 (or 430020 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 21500650 is about 4636.8793385207. The cubic root of 21500650 is about 278.0676905021.

The spelling of 21500650 in words is "twenty-one million, five hundred thousand, six hundred fifty".