21343037 has 4 divisors (see below), whose sum is σ = 21355740. Its totient is φ = 21330336.

The previous prime is 21343019. The next prime is 21343039. The reversal of 21343037 is 73034312.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18567481 + 2775556 = 4309^2 + 1666^2 .

It is a cyclic number.

It is not a de Polignac number, because 21343037 - 2¹⁸ = 21080893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21343039) 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, 3362 + ... + 7347.

It is an arithmetic number, because the mean of its divisors is an integer number (5338935).

Almost surely, 2^21343037 is an apocalyptic number.

It is an amenable number.

21343037 is a deficient number, since it is larger than the sum of its proper divisors (12703).

21343037 is a wasteful number, since it uses less digits than its factorization.

21343037 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12702.

The product of its (nonzero) digits is 1512, while the sum is 23.

The square root of 21343037 is about 4619.8524868225. The cubic root of 21343037 is about 277.3865542829.

Adding to 21343037 its reverse (73034312), we get a palindrome (94377349).

The spelling of 21343037 in words is "twenty-one million, three hundred forty-three thousand, thirty-seven".