21417453 has 20 divisors (see below), whose sum is σ = 32408640. Its totient is φ = 14093352.

The previous prime is 21417449. The next prime is 21417463. The reversal of 21417453 is 35471412.

It is not a de Polignac number, because 21417453 - 2² = 21417449 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21417463) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4726 + ... + 8072.

It is an arithmetic number, because the mean of its divisors is an integer number (1620432).

Almost surely, 2^21417453 is an apocalyptic number.

It is an amenable number.

21417453 is a deficient number, since it is larger than the sum of its proper divisors (10991187).

21417453 is an equidigital number, since it uses as much as digits as its factorization.

21417453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3438 (or 3429 counting only the distinct ones).

The product of its digits is 3360, while the sum is 27.

The square root of 21417453 is about 4627.8994155016. The cubic root of 21417453 is about 277.7085649011.

Adding to 21417453 its reverse (35471412), we get a palindrome (56888865).

The spelling of 21417453 in words is "twenty-one million, four hundred seventeen thousand, four hundred fifty-three".