21025534 has 8 divisors (see below), whose sum is σ = 31937760. Its totient is φ = 10379616.

The previous prime is 21025513. The next prime is 21025561. The reversal of 21025534 is 43552012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66379 + ... + 66694.

It is an arithmetic number, because the mean of its divisors is an integer number (3992220).

Almost surely, 2^21025534 is an apocalyptic number.

21025534 is a deficient number, since it is larger than the sum of its proper divisors (10912226).

21025534 is a wasteful number, since it uses less digits than its factorization.

21025534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133154.

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 21025534 is about 4585.3608364010. The cubic root of 21025534 is about 276.0041919828.

Adding to 21025534 its reverse (43552012), we get a palindrome (64577546).

The spelling of 21025534 in words is "twenty-one million, twenty-five thousand, five hundred thirty-four".