2138661 has 24 divisors (see below), whose sum is σ = 3581760. Its totient is φ = 1204416.

The previous prime is 2138657. The next prime is 2138671. The reversal of 2138661 is 1668312.

It is not a de Polignac number, because 2138661 - 2² = 2138657 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2138671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5025 + ... + 5433.

It is an arithmetic number, because the mean of its divisors is an integer number (149240).

2^2138661 is an apocalyptic number.

2138661 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2138661 is a deficient number, since it is larger than the sum of its proper divisors (1443099).

2138661 is a wasteful number, since it uses less digits than its factorization.

2138661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505 (or 502 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 2138661 is about 1462.4161514425. The cubic root of 2138661 is about 128.8389914806.

The spelling of 2138661 in words is "two million, one hundred thirty-eight thousand, six hundred sixty-one".