21512452 has 24 divisors (see below), whose sum is σ = 42307776. Its totient is φ = 9496608.

The previous prime is 21512431. The next prime is 21512459. The reversal of 21512452 is 25421512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21512459) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7798 + ... + 10189.

It is an arithmetic number, because the mean of its divisors is an integer number (1762824).

Almost surely, 2^21512452 is an apocalyptic number.

It is an amenable number.

21512452 is a deficient number, since it is larger than the sum of its proper divisors (20795324).

21512452 is a wasteful number, since it uses less digits than its factorization.

21512452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18027 (or 18025 counting only the distinct ones).

The product of its digits is 800, while the sum is 22.

The square root of 21512452 is about 4638.1517870807. The cubic root of 21512452 is about 278.1185595782.

Adding to 21512452 its reverse (25421512), we get a palindrome (46933964).

The spelling of 21512452 in words is "twenty-one million, five hundred twelve thousand, four hundred fifty-two".