13878464521 has 2 divisors, whose sum is σ = 13878464522. Its totient is φ = 13878464520.

The previous prime is 13878464447. The next prime is 13878464531. The reversal of 13878464521 is 12546487831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8382318025 + 5496146496 = 91555^2 + 74136^2 .

It is an emirp because it is prime and its reverse (12546487831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13878464521 - 2¹³ = 13878456329 is a prime.

It is a super-2 number, since 2×13878464521² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (13878464531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6939232260 + 6939232261.

It is an arithmetic number, because the mean of its divisors is an integer number (6939232261).

Almost surely, 2^13878464521 is an apocalyptic number.

It is an amenable number.

13878464521 is a deficient number, since it is larger than the sum of its proper divisors (1).

13878464521 is an equidigital number, since it uses as much as digits as its factorization.

13878464521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1290240, while the sum is 49.

The spelling of 13878464521 in words is "thirteen billion, eight hundred seventy-eight million, four hundred sixty-four thousand, five hundred twenty-one".