21976349 has 4 divisors (see below), whose sum is σ = 22055964. Its totient is φ = 21896736.

The previous prime is 21976343. The next prime is 21976351. The reversal of 21976349 is 94367912.

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 2992900 + 18983449 = 1730^2 + 4357^2 .

It is a cyclic number.

It is not a de Polignac number, because 21976349 - 2⁴ = 21976333 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 (21976343) 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, 39392 + ... + 39945.

It is an arithmetic number, because the mean of its divisors is an integer number (5513991).

Almost surely, 2^21976349 is an apocalyptic number.

It is an amenable number.

21976349 is a deficient number, since it is larger than the sum of its proper divisors (79615).

21976349 is an equidigital number, since it uses as much as digits as its factorization.

21976349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79614.

The product of its digits is 81648, while the sum is 41.

The square root of 21976349 is about 4687.8938767852. The cubic root of 21976349 is about 280.1034864072.

The spelling of 21976349 in words is "twenty-one million, nine hundred seventy-six thousand, three hundred forty-nine".