21307452 has 24 divisors (see below), whose sum is σ = 49803600. Its totient is φ = 7090176.

The previous prime is 21307441. The next prime is 21307457. The reversal of 21307452 is 25470312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21307457) 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, 8074 + ... + 10382.

It is an arithmetic number, because the mean of its divisors is an integer number (2075150).

Almost surely, 2^21307452 is an apocalyptic number.

It is an amenable number.

21307452 is an abundant number, since it is smaller than the sum of its proper divisors (28496148).

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

21307452 is a wasteful number, since it uses less digits than its factorization.

21307452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3085 (or 3083 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 21307452 is about 4615.9995667244. Note that the first 3 decimals coincide. The cubic root of 21307452 is about 277.2323073897.

Adding to 21307452 its reverse (25470312), we get a palindrome (46777764).

The spelling of 21307452 in words is "twenty-one million, three hundred seven thousand, four hundred fifty-two".