21672341 has 2 divisors, whose sum is σ = 21672342. Its totient is φ = 21672340.

The previous prime is 21672337. The next prime is 21672347. The reversal of 21672341 is 14327612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21585316 + 87025 = 4646^2 + 295^2 .

It is a cyclic number.

It is not a de Polignac number, because 21672341 - 2² = 21672337 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a self number, because there is not a number n which added to its sum of digits gives 21672341.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21672347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10836170 + 10836171.

It is an arithmetic number, because the mean of its divisors is an integer number (10836171).

Almost surely, 2^21672341 is an apocalyptic number.

It is an amenable number.

21672341 is a deficient number, since it is larger than the sum of its proper divisors (1).

21672341 is an equidigital number, since it uses as much as digits as its factorization.

21672341 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2016, while the sum is 26.

The square root of 21672341 is about 4655.3561625294. The cubic root of 21672341 is about 278.8058883695.

Adding to 21672341 its reverse (14327612), we get a palindrome (35999953).

The spelling of 21672341 in words is "twenty-one million, six hundred seventy-two thousand, three hundred forty-one".