21021052 has 12 divisors (see below), whose sum is σ = 39616696. Its totient is φ = 9702000.

The previous prime is 21021047. The next prime is 21021053. The reversal of 21021052 is 25012012.

21021052 is nontrivially palindromic in base 3.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021053) 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, 202074 + ... + 202177.

Almost surely, 2^21021052 is an apocalyptic number.

It is an amenable number.

21021052 is a deficient number, since it is larger than the sum of its proper divisors (18595644).

21021052 is a wasteful number, since it uses less digits than its factorization.

21021052 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404268 (or 404266 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 21021052 is about 4584.8720810945. The cubic root of 21021052 is about 275.9845787085.

Adding to 21021052 its reverse (25012012), we get a palindrome (46033064).

The spelling of 21021052 in words is "twenty-one million, twenty-one thousand, fifty-two".