21969373 has 4 divisors (see below), whose sum is σ = 21986748. Its totient is φ = 21952000.

The previous prime is 21969371. The next prime is 21969397. The reversal of 21969373 is 37396912.

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 20593444 + 1375929 = 4538^2 + 1173^2 .

It is a cyclic number.

It is not a de Polignac number, because 21969373 - 2¹ = 21969371 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 (21969371) 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, 6628 + ... + 9373.

It is an arithmetic number, because the mean of its divisors is an integer number (5496687).

Almost surely, 2^21969373 is an apocalyptic number.

It is an amenable number.

21969373 is a deficient number, since it is larger than the sum of its proper divisors (17375).

21969373 is a wasteful number, since it uses less digits than its factorization.

21969373 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17374.

The product of its digits is 61236, while the sum is 40.

The square root of 21969373 is about 4687.1497735831. The cubic root of 21969373 is about 280.0738453187.

The spelling of 21969373 in words is "twenty-one million, nine hundred sixty-nine thousand, three hundred seventy-three".