21452013 has 16 divisors (see below), whose sum is σ = 34670400. Its totient is φ = 13001040.

The previous prime is 21451981. The next prime is 21452021. The reversal of 21452013 is 31025412.

It is not a de Polignac number, because 21452013 - 2⁵ = 21451981 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21452063) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35818 + ... + 36411.

It is an arithmetic number, because the mean of its divisors is an integer number (2166900).

Almost surely, 2^21452013 is an apocalyptic number.

It is an amenable number.

21452013 is a deficient number, since it is larger than the sum of its proper divisors (13218387).

21452013 is a wasteful number, since it uses less digits than its factorization.

21452013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72249 (or 72243 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 21452013 is about 4631.6317858828. The cubic root of 21452013 is about 277.8578582566.

Adding to 21452013 its reverse (31025412), we get a palindrome (52477425).

The spelling of 21452013 in words is "twenty-one million, four hundred fifty-two thousand, thirteen".