21532373 has 2 divisors, whose sum is σ = 21532374. Its totient is φ = 21532372.

The previous prime is 21532361. The next prime is 21532403. The reversal of 21532373 is 37323512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11785489 + 9746884 = 3433^2 + 3122^2 .

It is a cyclic number.

It is not a de Polignac number, because 21532373 - 2⁶ = 21532309 is a prime.

It is a super-2 number, since 2×21532373² = 927286174022258, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21532333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10766186 + 10766187.

It is an arithmetic number, because the mean of its divisors is an integer number (10766187).

Almost surely, 2^21532373 is an apocalyptic number.

It is an amenable number.

21532373 is a deficient number, since it is larger than the sum of its proper divisors (1).

21532373 is an equidigital number, since it uses as much as digits as its factorization.

21532373 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3780, while the sum is 26.

The square root of 21532373 is about 4640.2988050340. The cubic root of 21532373 is about 278.2043810445.

Adding to 21532373 its reverse (37323512), we get a palindrome (58855885).

The spelling of 21532373 in words is "twenty-one million, five hundred thirty-two thousand, three hundred seventy-three".