21343437 has 24 divisors (see below), whose sum is σ = 31862688. Its totient is φ = 13759200.

The previous prime is 21343429. The next prime is 21343451. The reversal of 21343437 is 73434312.

It is not a de Polignac number, because 21343437 - 2³ = 21343429 is a prime.

It is a super-3 number, since 3×21343437³ (a number of 23 digits) contains 333 as substring.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 21343437.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21343457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50487 + ... + 50907.

It is an arithmetic number, because the mean of its divisors is an integer number (1327612).

Almost surely, 2^21343437 is an apocalyptic number.

It is an amenable number.

21343437 is a deficient number, since it is larger than the sum of its proper divisors (10519251).

21343437 is a wasteful number, since it uses less digits than its factorization.

21343437 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 601 (or 598 counting only the distinct ones).

The product of its digits is 6048, while the sum is 27.

The square root of 21343437 is about 4619.8957780452. The cubic root of 21343437 is about 277.3882871498.

Adding to 21343437 its reverse (73434312), we get a palindrome (94777749).

The spelling of 21343437 in words is "twenty-one million, three hundred forty-three thousand, four hundred thirty-seven".