21737345 has 16 divisors (see below), whose sum is σ = 29922048. Its totient is φ = 14850240.

The previous prime is 21737333. The next prime is 21737347. The reversal of 21737345 is 54373712.

It is not a de Polignac number, because 21737345 - 2⁴ = 21737329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21737347) 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 15 ways as a sum of consecutive naturals, for example, 9887 + ... + 11883.

It is an arithmetic number, because the mean of its divisors is an integer number (1870128).

Almost surely, 2^21737345 is an apocalyptic number.

It is an amenable number.

21737345 is a deficient number, since it is larger than the sum of its proper divisors (8184703).

21737345 is a wasteful number, since it uses less digits than its factorization.

21737345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2320.

The product of its digits is 17640, while the sum is 32.

The square root of 21737345 is about 4662.3325707204. The cubic root of 21737345 is about 279.0843601820.

The spelling of 21737345 in words is "twenty-one million, seven hundred thirty-seven thousand, three hundred forty-five".