21967345 has 8 divisors (see below), whose sum is σ = 26441064. Its totient is φ = 17520384.

The previous prime is 21967343. The next prime is 21967397. The reversal of 21967345 is 54376912.

It can be written as a sum of positive squares in 4 ways, for example, as 1825201 + 20142144 = 1351^2 + 4488^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21967345 - 2¹ = 21967343 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21967343) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4834 + ... + 8203.

It is an arithmetic number, because the mean of its divisors is an integer number (3305133).

Almost surely, 2^21967345 is an apocalyptic number.

It is an amenable number.

21967345 is a deficient number, since it is larger than the sum of its proper divisors (4473719).

21967345 is a wasteful number, since it uses less digits than its factorization.

21967345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13379.

The product of its digits is 45360, while the sum is 37.

The square root of 21967345 is about 4686.9334324268. The cubic root of 21967345 is about 280.0652271508.

The spelling of 21967345 in words is "twenty-one million, nine hundred sixty-seven thousand, three hundred forty-five".