21012574 has 16 divisors (see below), whose sum is σ = 34462080. Its totient is φ = 9529560.

The previous prime is 21012569. The next prime is 21012581. The reversal of 21012574 is 47521012.

It is a happy number.

It is a super-2 number, since 2×21012574² = 883056532210952, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12847 + ... + 14389.

It is an arithmetic number, because the mean of its divisors is an integer number (2153880).

Almost surely, 2^21012574 is an apocalyptic number.

21012574 is a deficient number, since it is larger than the sum of its proper divisors (13449506).

21012574 is a wasteful number, since it uses less digits than its factorization.

21012574 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2175.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 21012574 is about 4583.9474255275. The cubic root of 21012574 is about 275.9474712747.

Adding to 21012574 its reverse (47521012), we get a palindrome (68533586).

The spelling of 21012574 in words is "twenty-one million, twelve thousand, five hundred seventy-four".