21421534 has 8 divisors (see below), whose sum is σ = 32168880. Its totient is φ = 10698576.

The previous prime is 21421489. The next prime is 21421537. The reversal of 21421534 is 43512412.

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

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21421537) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3714 + ... + 7525.

It is an arithmetic number, because the mean of its divisors is an integer number (4021110).

Almost surely, 2^21421534 is an apocalyptic number.

21421534 is a deficient number, since it is larger than the sum of its proper divisors (10747346).

21421534 is a wasteful number, since it uses less digits than its factorization.

21421534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12194.

The product of its digits is 960, while the sum is 22.

The square root of 21421534 is about 4628.3403072808. The cubic root of 21421534 is about 277.7262024897.

Adding to 21421534 its reverse (43512412), we get a palindrome (64933946).

The spelling of 21421534 in words is "twenty-one million, four hundred twenty-one thousand, five hundred thirty-four".