18191064541 has 32 divisors (see below), whose sum is σ = 20764100448. Its totient is φ = 15820738560.

The previous prime is 18191064511. The next prime is 18191064571. The reversal of 18191064541 is 14546019181.

18191064541 = 95370² + 95371².

It is an interprime number because it is at equal distance from previous prime (18191064511) and next prime (18191064571).

It can be written as a sum of positive squares in 16 ways, for example, as 1048399641 + 17142664900 = 32379^2 + 130930^2 .

It is a 6-Lehmer number, since φ(18191064541) divides (18191064541-1)⁶.

It is a cyclic number.

It is not a de Polignac number, because 18191064541 - 2⁵ = 18191064509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18191064494 and 18191064503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18191064511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2698411 + ... + 2705143.

It is an arithmetic number, because the mean of its divisors is an integer number (648878139).

Almost surely, 2^18191064541 is an apocalyptic number.

18191064541 is the 95371-st centered square number.

It is an amenable number.

18191064541 is a deficient number, since it is larger than the sum of its proper divisors (2573035907).

18191064541 is a wasteful number, since it uses less digits than its factorization.

18191064541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6961.

The product of its (nonzero) digits is 34560, while the sum is 40.

The spelling of 18191064541 in words is "eighteen billion, one hundred ninety-one million, sixty-four thousand, five hundred forty-one".