16081661 has 8 divisors (see below), whose sum is σ = 16498944. Its totient is φ = 15667600.

The previous prime is 16081633. The next prime is 16081679. The reversal of 16081661 is 16618061.

16081661 = 84² + 85² + ... + 365².

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16081661 - 2¹⁴ = 16065277 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 (16081601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11711 + ... + 13011.

It is an arithmetic number, because the mean of its divisors is an integer number (2062368).

Almost surely, 2^16081661 is an apocalyptic number.

It is an amenable number.

16081661 is a deficient number, since it is larger than the sum of its proper divisors (417283).

16081661 is a wasteful number, since it uses less digits than its factorization.

16081661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1611.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 16081661 is about 4010.1946336805. The cubic root of 16081661 is about 252.4121761033.

The spelling of 16081661 in words is "sixteen million, eighty-one thousand, six hundred sixty-one".