1938661 has 4 divisors (see below), whose sum is σ = 1965292. Its totient is φ = 1912032.

The previous prime is 1938659. The next prime is 1938701. The reversal of 1938661 is 1668391.

1938661 = T₁₉₃ + T₁₉₄ + ... + T₂₆₅.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1668391 = 1153 ⋅1447.

It can be written as a sum of positive squares in 2 ways, for example, as 988036 + 950625 = 994^2 + 975^2 .

It is a cyclic number.

It is not a de Polignac number, because 1938661 - 2¹ = 1938659 is a prime.

It is an Ulam number.

It is a Duffinian number.

1938661 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1938611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13206 + ... + 13351.

It is an arithmetic number, because the mean of its divisors is an integer number (491323).

2^1938661 is an apocalyptic number.

It is an amenable number.

1938661 is a deficient number, since it is larger than the sum of its proper divisors (26631).

1938661 is an equidigital number, since it uses as much as digits as its factorization.

1938661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26630.

The product of its digits is 7776, while the sum is 34.

The square root of 1938661 is about 1392.3580717617. The cubic root of 1938661 is about 124.6906698168.

The spelling of 1938661 in words is "one million, nine hundred thirty-eight thousand, six hundred sixty-one".