21453073 has 4 divisors (see below), whose sum is σ = 21467248. Its totient is φ = 21438900.

The previous prime is 21453067. The next prime is 21453079. The reversal of 21453073 is 37035412.

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 an interprime number because it is at equal distance from previous prime (21453067) and next prime (21453079).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21453073 is a prime.

It is a super-2 number, since 2×21453073² = 920468682286658, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21453079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4503 + ... + 7948.

It is an arithmetic number, because the mean of its divisors is an integer number (5366812).

Almost surely, 2^21453073 is an apocalyptic number.

It is an amenable number.

21453073 is a deficient number, since it is larger than the sum of its proper divisors (14175).

21453073 is a wasteful number, since it uses less digits than its factorization.

21453073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14174.

The product of its (nonzero) digits is 2520, while the sum is 25.

The square root of 21453073 is about 4631.7462149820. The cubic root of 21453073 is about 277.8624347421.

Adding to 21453073 its reverse (37035412), we get a palindrome (58488485).

The spelling of 21453073 in words is "twenty-one million, four hundred fifty-three thousand, seventy-three".