21801652 has 12 divisors (see below), whose sum is σ = 38251780. Its totient is φ = 10872576.

The previous prime is 21801641. The next prime is 21801653. The reversal of 21801652 is 25610812.

It can be written as a sum of positive squares in 2 ways, for example, as 11329956 + 10471696 = 3366^2 + 3236^2 .

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 5277 + ... + 8452.

Almost surely, 2^21801652 is an apocalyptic number.

It is an amenable number.

21801652 is a deficient number, since it is larger than the sum of its proper divisors (16450128).

21801652 is a wasteful number, since it uses less digits than its factorization.

21801652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14130 (or 14128 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 21801652 is about 4669.2239183830. The cubic root of 21801652 is about 279.3593003671.

The spelling of 21801652 in words is "twenty-one million, eight hundred one thousand, six hundred fifty-two".