1376686921 has 4 divisors (see below), whose sum is σ = 1376869572. Its totient is φ = 1376504272.

The previous prime is 1376686907. The next prime is 1376686957. The reversal of 1376686921 is 1296866731.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1296866731 = 587 ⋅2209313.

It can be written as a sum of positive squares in 2 ways, for example, as 935686921 + 441000000 = 30589^2 + 21000^2 .

It is a cyclic number.

It is not a de Polignac number, because 1376686921 - 2¹³ = 1376678729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1376681921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79510 + ... + 95263.

It is an arithmetic number, because the mean of its divisors is an integer number (344217393).

Almost surely, 2^1376686921 is an apocalyptic number.

It is an amenable number.

1376686921 is a deficient number, since it is larger than the sum of its proper divisors (182651).

1376686921 is an equidigital number, since it uses as much as digits as its factorization.

1376686921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182650.

The product of its digits is 653184, while the sum is 49.

The square root of 1376686921 is about 37103.7319012522. The cubic root of 1376686921 is about 1112.4446083770. Note that the first 3 decimals are identical.

The spelling of 1376686921 in words is "one billion, three hundred seventy-six million, six hundred eighty-six thousand, nine hundred twenty-one".