16661470531 has 4 divisors (see below), whose sum is σ = 17015969952. Its totient is φ = 16306971112.

The previous prime is 16661470499. The next prime is 16661470597. The reversal of 16661470531 is 13507416661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13507416661 = 35129 ⋅384509.

It is a cyclic number.

It is not a de Polignac number, because 16661470531 - 2⁵ = 16661470499 is a prime.

It is a super-2 number, since 2×16661470531² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16661473531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 177249640 + ... + 177249733.

It is an arithmetic number, because the mean of its divisors is an integer number (4253992488).

Almost surely, 2^16661470531 is an apocalyptic number.

16661470531 is a deficient number, since it is larger than the sum of its proper divisors (354499421).

16661470531 is an equidigital number, since it uses as much as digits as its factorization.

16661470531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 354499420.

The product of its (nonzero) digits is 90720, while the sum is 40.

The spelling of 16661470531 in words is "sixteen billion, six hundred sixty-one million, four hundred seventy thousand, five hundred thirty-one".