21801650 has 48 divisors (see below), whose sum is σ = 46262664. Its totient is φ = 7572480.

The previous prime is 21801641. The next prime is 21801653. The reversal of 21801650 is 5610812.

It can be written as a sum of positive squares in 12 ways, for example, as 58081 + 21743569 = 241^2 + 4663^2 .

It is not an unprimeable number, because it can be changed into a prime (21801653) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10064 + ... + 12036.

Almost surely, 2^21801650 is an apocalyptic number.

21801650 is an abundant number, since it is smaller than the sum of its proper divisors (24461014).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21801650 is a wasteful number, since it uses less digits than its factorization.

21801650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2015 (or 2010 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 21801650 is about 4669.2237042147. The cubic root of 21801650 is about 279.3592918247.

The spelling of 21801650 in words is "twenty-one million, eight hundred one thousand, six hundred fifty".