16531661545 has 16 divisors (see below), whose sum is σ = 23043667968. Its totient is φ = 11150159040.

The previous prime is 16531661507. The next prime is 16531661603. The reversal of 16531661545 is 54516613561.

It is not a de Polignac number, because 16531661545 - 2²¹ = 16529564393 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 3869449 + ... + 3873718.

It is an arithmetic number, because the mean of its divisors is an integer number (1440229248).

Almost surely, 2^16531661545 is an apocalyptic number.

It is an amenable number.

16531661545 is a deficient number, since it is larger than the sum of its proper divisors (6512006423).

16531661545 is an equidigital number, since it uses as much as digits as its factorization.

16531661545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7743240.

The product of its digits is 324000, while the sum is 43.

The spelling of 16531661545 in words is "sixteen billion, five hundred thirty-one million, six hundred sixty-one thousand, five hundred forty-five".