21352453 has 4 divisors (see below), whose sum is σ = 21480480. Its totient is φ = 21224428.

The previous prime is 21352451. The next prime is 21352477. The reversal of 21352453 is 35425312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21352453 - 2¹ = 21352451 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21352451) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63763 + ... + 64096.

It is an arithmetic number, because the mean of its divisors is an integer number (5370120).

Almost surely, 2^21352453 is an apocalyptic number.

It is an amenable number.

21352453 is a deficient number, since it is larger than the sum of its proper divisors (128027).

21352453 is a wasteful number, since it uses less digits than its factorization.

21352453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128026.

The product of its digits is 3600, while the sum is 25.

The square root of 21352453 is about 4620.8714546068. The cubic root of 21352453 is about 277.4273402278.

Adding to 21352453 its reverse (35425312), we get a palindrome (56777765).

The spelling of 21352453 in words is "twenty-one million, three hundred fifty-two thousand, four hundred fifty-three".