21352073 has 4 divisors (see below), whose sum is σ = 22280448. Its totient is φ = 20423700.

The previous prime is 21352069. The next prime is 21352099. The reversal of 21352073 is 37025312.

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 21352073 - 2² = 21352069 is a prime.

It is a super-2 number, since 2×21352073² = 911822042794658, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 928351 = 21352073 / (2 + 1 + 3 + 5 + 2 + 0 + 7 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21351073) 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, 464153 + ... + 464198.

It is an arithmetic number, because the mean of its divisors is an integer number (5570112).

Almost surely, 2^21352073 is an apocalyptic number.

21352073 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21352073 is a deficient number, since it is larger than the sum of its proper divisors (928375).

21352073 is an equidigital number, since it uses as much as digits as its factorization.

21352073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 928374.

The product of its (nonzero) digits is 1260, while the sum is 23.

The square root of 21352073 is about 4620.8303366386. The cubic root of 21352073 is about 277.4256944682.

Adding to 21352073 its reverse (37025312), we get a palindrome (58377385).

The spelling of 21352073 in words is "twenty-one million, three hundred fifty-two thousand, seventy-three".