21125534 has 8 divisors (see below), whose sum is σ = 31806048. Its totient is φ = 10523520.

The previous prime is 21125521. The next prime is 21125551. The reversal of 21125534 is 43552112.

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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18947 + ... + 20030.

It is an arithmetic number, because the mean of its divisors is an integer number (3975756).

Almost surely, 2^21125534 is an apocalyptic number.

21125534 is a deficient number, since it is larger than the sum of its proper divisors (10680514).

21125534 is a wasteful number, since it uses less digits than its factorization.

21125534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39250.

The product of its digits is 1200, while the sum is 23.

The square root of 21125534 is about 4596.2521688872. The cubic root of 21125534 is about 276.4410699470.

Adding to 21125534 its reverse (43552112), we get a palindrome (64677646).

The spelling of 21125534 in words is "twenty-one million, one hundred twenty-five thousand, five hundred thirty-four".