1375853661 has 32 divisors (see below), whose sum is σ = 2508683520. Its totient is φ = 725723712.

The previous prime is 1375853623. The next prime is 1375853663. The reversal of 1375853661 is 1663585731.

1375853661 is a `hidden beast` number, since 1 + 3 + 7 + 58 + 536 + 61 = 666.

It is not a de Polignac number, because 1375853661 - 2⁷ = 1375853533 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1375853663) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 277530 + ... + 282443.

It is an arithmetic number, because the mean of its divisors is an integer number (78396360).

Almost surely, 2^1375853661 is an apocalyptic number.

It is an amenable number.

1375853661 is a deficient number, since it is larger than the sum of its proper divisors (1132829859).

1375853661 is a wasteful number, since it uses less digits than its factorization.

1375853661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 560002 (or 559996 counting only the distinct ones).

The product of its digits is 453600, while the sum is 45.

The square root of 1375853661 is about 37092.5014120105. The cubic root of 1375853661 is about 1112.2201219280.

It can be divided in two parts, 137585 and 3661, that added together give a triangular number (141246 = T₅₃₁).

The spelling of 1375853661 in words is "one billion, three hundred seventy-five million, eight hundred fifty-three thousand, six hundred sixty-one".