21511452 has 12 divisors (see below), whose sum is σ = 50193416. Its totient is φ = 7170480.

The previous prime is 21511433. The next prime is 21511493. The reversal of 21511452 is 25411512.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 896299 + ... + 896322.

Almost surely, 2^21511452 is an apocalyptic number.

It is an amenable number.

21511452 is an abundant number, since it is smaller than the sum of its proper divisors (28681964).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21511452 is a wasteful number, since it uses less digits than its factorization.

21511452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1792628 (or 1792626 counting only the distinct ones).

The product of its digits is 400, while the sum is 21.

The square root of 21511452 is about 4638.0439842675. The cubic root of 21511452 is about 278.1142500916.

Adding to 21511452 its reverse (25411512), we get a palindrome (46922964).

The spelling of 21511452 in words is "twenty-one million, five hundred eleven thousand, four hundred fifty-two".