1375931681 has 6 divisors (see below), whose sum is σ = 1378545510. Its totient is φ = 1373321216.

The previous prime is 1375931663. The next prime is 1375931699. The reversal of 1375931681 is 1861395731.

It is an interprime number because it is at equal distance from previous prime (1375931663) and next prime (1375931699).

It can be written as a sum of positive squares in 3 ways, for example, as 13140625 + 1362791056 = 3625^2 + 36916^2 .

It is not a de Polignac number, because 1375931681 - 2¹⁴ = 1375915297 is a prime.

It is a super-2 number, since 2×1375931681² = 3786375981558971522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1375931581) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1129985 + ... + 1131201.

It is an arithmetic number, because the mean of its divisors is an integer number (229757585).

Almost surely, 2^1375931681 is an apocalyptic number.

It is an amenable number.

1375931681 is a deficient number, since it is larger than the sum of its proper divisors (2613829).

1375931681 is an frugal number, since it uses more digits than its factorization.

1375931681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3363 (or 2146 counting only the distinct ones).

The product of its digits is 136080, while the sum is 44.

The square root of 1375931681 is about 37093.5530921480. The cubic root of 1375931681 is about 1112.2411449423.

The spelling of 1375931681 in words is "one billion, three hundred seventy-five million, nine hundred thirty-one thousand, six hundred eighty-one".