21014381 has 2 divisors, whose sum is σ = 21014382. Its totient is φ = 21014380.

The previous prime is 21014351. The next prime is 21014407. The reversal of 21014381 is 18341012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20475625 + 538756 = 4525^2 + 734^2 .

It is a cyclic number.

It is not a de Polignac number, because 21014381 - 2¹⁰ = 21013357 is a prime.

It is a super-2 number, since 2×21014381² = 883208417626322, which contains 22 as substring.

It is a Chen prime.

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

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21014351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10507190 + 10507191.

It is an arithmetic number, because the mean of its divisors is an integer number (10507191).

Almost surely, 2^21014381 is an apocalyptic number.

It is an amenable number.

21014381 is a deficient number, since it is larger than the sum of its proper divisors (1).

21014381 is an equidigital number, since it uses as much as digits as its factorization.

21014381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 21014381 is about 4584.1445221546. The cubic root of 21014381 is about 275.9553811860.

Adding to 21014381 its reverse (18341012), we get a palindrome (39355393).

The spelling of 21014381 in words is "twenty-one million, fourteen thousand, three hundred eighty-one".