21217050 has 36 divisors (see below), whose sum is σ = 57004350. Its totient is φ = 5657760.

The previous prime is 21217039. The next prime is 21217087. The reversal of 21217050 is 5071212.

It can be written as a sum of positive squares in 3 ways, for example, as 8105409 + 13111641 = 2847^2 + 3621^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 23125 + ... + 24024.

Almost surely, 2^21217050 is an apocalyptic number.

21217050 is an abundant number, since it is smaller than the sum of its proper divisors (35787300).

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

21217050 is a wasteful number, since it uses less digits than its factorization.

21217050 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47167 (or 47159 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

The square root of 21217050 is about 4606.1969128556. The cubic root of 21217050 is about 276.8396766301.

Adding to 21217050 its reverse (5071212), we get a palindrome (26288262).

The spelling of 21217050 in words is "twenty-one million, two hundred seventeen thousand, fifty".