16140661 has 4 divisors (see below), whose sum is σ = 16405324. Its totient is φ = 15876000.

The previous prime is 16140659. The next prime is 16140679. The reversal of 16140661 is 16604161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16604161 = 7 ⋅2372023.

It can be written as a sum of positive squares in 2 ways, for example, as 3538161 + 12602500 = 1881^2 + 3550^2 .

It is a cyclic number.

It is not a de Polignac number, because 16140661 - 2¹ = 16140659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16140601) 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, 132240 + ... + 132361.

It is an arithmetic number, because the mean of its divisors is an integer number (4101331).

Almost surely, 2^16140661 is an apocalyptic number.

It is an amenable number.

16140661 is a deficient number, since it is larger than the sum of its proper divisors (264663).

16140661 is an equidigital number, since it uses as much as digits as its factorization.

16140661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264662.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 16140661 is about 4017.5441503486. The cubic root of 16140661 is about 252.7204805591.

The spelling of 16140661 in words is "sixteen million, one hundred forty thousand, six hundred sixty-one".