21240010 has 32 divisors (see below), whose sum is σ = 41902272. Its totient is φ = 7687680.

The previous prime is 21240001. The next prime is 21240049. The reversal of 21240010 is 1004212.

It is a super-2 number, since 2×21240010² = 902276049600200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38557 + ... + 39103.

It is an arithmetic number, because the mean of its divisors is an integer number (1309446).

Almost surely, 2^21240010 is an apocalyptic number.

21240010 is a deficient number, since it is larger than the sum of its proper divisors (20662262).

21240010 is a wasteful number, since it uses less digits than its factorization.

21240010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 918.

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 21240010 is about 4608.6885336286. The cubic root of 21240010 is about 276.9395011824.

Adding to 21240010 its reverse (1004212), we get a palindrome (22244222).

The spelling of 21240010 in words is "twenty-one million, two hundred forty thousand, ten".