13771621 has 2 divisors, whose sum is σ = 13771622. Its totient is φ = 13771620.

The previous prime is 13771619. The next prime is 13771627. The reversal of 13771621 is 12617731.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13771521 + 100 = 3711^2 + 10^2 .

It is a cyclic number.

It is not a de Polignac number, because 13771621 - 2¹ = 13771619 is a prime.

Together with 13771619, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 13771621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13771627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6885810 + 6885811.

It is an arithmetic number, because the mean of its divisors is an integer number (6885811).

Almost surely, 2^13771621 is an apocalyptic number.

It is an amenable number.

13771621 is a deficient number, since it is larger than the sum of its proper divisors (1).

13771621 is an equidigital number, since it uses as much as digits as its factorization.

13771621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1764, while the sum is 28.

The square root of 13771621 is about 3711.0134734328. The cubic root of 13771621 is about 239.6964971406.

The spelling of 13771621 in words is "thirteen million, seven hundred seventy-one thousand, six hundred twenty-one".