21152534 has 8 divisors (see below), whose sum is σ = 34169520. Its totient is φ = 9762696.

The previous prime is 21152519. The next prime is 21152561. The reversal of 21152534 is 43525112.

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, 406754 + ... + 406805.

It is an arithmetic number, because the mean of its divisors is an integer number (4271190).

Almost surely, 2^21152534 is an apocalyptic number.

21152534 is a deficient number, since it is larger than the sum of its proper divisors (13016986).

21152534 is a wasteful number, since it uses less digits than its factorization.

21152534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 813574.

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

The square root of 21152534 is about 4599.1884066648. The cubic root of 21152534 is about 276.5587905426.

Adding to 21152534 its reverse (43525112), we get a palindrome (64677646).

The spelling of 21152534 in words is "twenty-one million, one hundred fifty-two thousand, five hundred thirty-four".