16408401991 has 2 divisors, whose sum is σ = 16408401992. Its totient is φ = 16408401990.

The previous prime is 16408401983. The next prime is 16408402027. The reversal of 16408401991 is 19910480461.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 16408401991 - 2³ = 16408401983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16408401391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8204200995 + 8204200996.

It is an arithmetic number, because the mean of its divisors is an integer number (8204200996).

Almost surely, 2^16408401991 is an apocalyptic number.

16408401991 is a deficient number, since it is larger than the sum of its proper divisors (1).

16408401991 is an equidigital number, since it uses as much as digits as its factorization.

16408401991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 62208, while the sum is 43.

The spelling of 16408401991 in words is "sixteen billion, four hundred eight million, four hundred one thousand, nine hundred ninety-one".