21034242 has 20 divisors (see below), whose sum is σ = 47132646. Its totient is φ = 7011360.

The previous prime is 21034231. The next prime is 21034249. The reversal of 21034242 is 24243012.

It can be written as a sum of positive squares in only one way, i.e., 16329681 + 4704561 = 4041^2 + 2169^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21034249) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 64759 + ... + 65082.

Almost surely, 2^21034242 is an apocalyptic number.

21034242 is an abundant number, since it is smaller than the sum of its proper divisors (26098404).

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

21034242 is a wasteful number, since it uses less digits than its factorization.

21034242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129855 (or 129846 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 21034242 is about 4586.3102816970. The cubic root of 21034242 is about 276.0422903061.

Adding to 21034242 its reverse (24243012), we get a palindrome (45277254).

The spelling of 21034242 in words is "twenty-one million, thirty-four thousand, two hundred forty-two".