16143991 has 2 divisors, whose sum is σ = 16143992. Its totient is φ = 16143990.

The previous prime is 16143979. The next prime is 16143997. The reversal of 16143991 is 19934161.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16143991 - 2¹¹ = 16141943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16143997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8071995 + 8071996.

It is an arithmetic number, because the mean of its divisors is an integer number (8071996).

Almost surely, 2^16143991 is an apocalyptic number.

16143991 is a deficient number, since it is larger than the sum of its proper divisors (1).

16143991 is an equidigital number, since it uses as much as digits as its factorization.

16143991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 34.

The square root of 16143991 is about 4017.9585612597. The cubic root of 16143991 is about 252.7378590570.

The spelling of 16143991 in words is "sixteen million, one hundred forty-three thousand, nine hundred ninety-one".