13811887421 has 2 divisors, whose sum is σ = 13811887422. Its totient is φ = 13811887420.

The previous prime is 13811887409. The next prime is 13811887457. The reversal of 13811887421 is 12478811831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8966196100 + 4845691321 = 94690^2 + 69611^2 .

It is an emirp because it is prime and its reverse (12478811831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13811887421 - 2¹⁸ = 13811625277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13811857421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6905943710 + 6905943711.

It is an arithmetic number, because the mean of its divisors is an integer number (6905943711).

Almost surely, 2^13811887421 is an apocalyptic number.

It is an amenable number.

13811887421 is a deficient number, since it is larger than the sum of its proper divisors (1).

13811887421 is an equidigital number, since it uses as much as digits as its factorization.

13811887421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 86016, while the sum is 44.

The spelling of 13811887421 in words is "thirteen billion, eight hundred eleven million, eight hundred eighty-seven thousand, four hundred twenty-one".