16540111981 has 16 divisors (see below), whose sum is σ = 17769787200. Its totient is φ = 15365484288.

The previous prime is 16540111963. The next prime is 16540111999. The reversal of 16540111981 is 18911104561.

It is an interprime number because it is at equal distance from previous prime (16540111963) and next prime (16540111999).

It is a cyclic number.

It is not a de Polignac number, because 16540111981 - 2⁵ = 16540111949 is a prime.

It is a super-2 number, since 2×16540111981² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16540111981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16540111901) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15436 + ... + 182533.

It is an arithmetic number, because the mean of its divisors is an integer number (1110611700).

Almost surely, 2^16540111981 is an apocalyptic number.

It is an amenable number.

16540111981 is a deficient number, since it is larger than the sum of its proper divisors (1229675219).

16540111981 is a wasteful number, since it uses less digits than its factorization.

16540111981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198108.

The product of its (nonzero) digits is 8640, while the sum is 37.

The spelling of 16540111981 in words is "sixteen billion, five hundred forty million, one hundred eleven thousand, nine hundred eighty-one".