16641557 has 2 divisors, whose sum is σ = 16641558. Its totient is φ = 16641556.

The previous prime is 16641553. The next prime is 16641571. The reversal of 16641557 is 75514661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16370116 + 271441 = 4046^2 + 521^2 .

It is a cyclic number.

It is not a de Polignac number, because 16641557 - 2² = 16641553 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16641553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8320778 + 8320779.

It is an arithmetic number, because the mean of its divisors is an integer number (8320779).

Almost surely, 2^16641557 is an apocalyptic number.

It is an amenable number.

16641557 is a deficient number, since it is larger than the sum of its proper divisors (1).

16641557 is an equidigital number, since it uses as much as digits as its factorization.

16641557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25200, while the sum is 35.

The square root of 16641557 is about 4079.4064519241. The cubic root of 16641557 is about 255.3081344939.

The spelling of 16641557 in words is "sixteen million, six hundred forty-one thousand, five hundred fifty-seven".