13938871969 has 9 divisors (see below), whose sum is σ = 15322667059. Its totient is φ = 12670521160.

The previous prime is 13938871957. The next prime is 13938871987. The reversal of 13938871969 is 96917883931.

The square root of 13938871969 is 118063.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 1121915025 + 12816956944 = 33495^2 + 113212^2 .

It is not a de Polignac number, because 13938871969 - 2⁷ = 13938871841 is a prime.

It is a super-2 number, since 2×13938871969² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13938871969.

It is not an unprimeable number, because it can be changed into a prime (13938871909) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1293327 + ... + 1304059.

Almost surely, 2^13938871969 is an apocalyptic number.

13938871969 is the 118063-rd square number.

13938871969 is the 59032-nd centered octagonal number.

It is an amenable number.

13938871969 is a deficient number, since it is larger than the sum of its proper divisors (1383795090).

13938871969 is an frugal number, since it uses more digits than its factorization.

13938871969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21488 (or 10744 counting only the distinct ones).

The product of its digits is 17635968, while the sum is 64.

Multiplying 13938871969 by its sum of digits (64), we get a square (892087806016 = 944504²).

The spelling of 13938871969 in words is "thirteen billion, nine hundred thirty-eight million, eight hundred seventy-one thousand, nine hundred sixty-nine".