21799850 has 12 divisors (see below), whose sum is σ = 40547814. Its totient is φ = 8719920.

The previous prime is 21799849. The next prime is 21799871. The reversal of 21799850 is 5899712.

It can be written as a sum of positive squares in 3 ways, for example, as 20133169 + 1666681 = 4487^2 + 1291^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21799798 and 21799807.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 217949 + ... + 218048.

Almost surely, 2^21799850 is an apocalyptic number.

21799850 is a deficient number, since it is larger than the sum of its proper divisors (18747964).

21799850 is a wasteful number, since it uses less digits than its factorization.

21799850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 436009 (or 436004 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 41.

The square root of 21799850 is about 4669.0309487087. The cubic root of 21799850 is about 279.3516034071.

The spelling of 21799850 in words is "twenty-one million, seven hundred ninety-nine thousand, eight hundred fifty".