16491257 has 2 divisors, whose sum is σ = 16491258. Its totient is φ = 16491256.

The previous prime is 16491203. The next prime is 16491263. The reversal of 16491257 is 75219461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16410601 + 80656 = 4051^2 + 284^2 .

It is a cyclic number.

It is not a de Polignac number, because 16491257 - 2⁸ = 16491001 is a prime.

It is not a weakly prime, because it can be changed into another prime (16491157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8245628 + 8245629.

It is an arithmetic number, because the mean of its divisors is an integer number (8245629).

Almost surely, 2^16491257 is an apocalyptic number.

It is an amenable number.

16491257 is a deficient number, since it is larger than the sum of its proper divisors (1).

16491257 is an equidigital number, since it uses as much as digits as its factorization.

16491257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 35.

The square root of 16491257 is about 4060.9428708121. The cubic root of 16491257 is about 254.5371946415.

The spelling of 16491257 in words is "sixteen million, four hundred ninety-one thousand, two hundred fifty-seven".