16531342785 has 16 divisors (see below), whose sum is σ = 29389054080. Its totient is φ = 8816716080.

The previous prime is 16531342783. The next prime is 16531342799. The reversal of 16531342785 is 58724313561.

It is a happy number.

16531342785 is a `hidden beast` number, since 1 + 6 + 531 + 3 + 42 + 78 + 5 = 666.

It is not a de Polignac number, because 16531342785 - 2¹ = 16531342783 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 16531342785.

It is not an unprimeable number, because it can be changed into a prime (16531342781) 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, 61227061 + ... + 61227330.

It is an arithmetic number, because the mean of its divisors is an integer number (1836815880).

Almost surely, 2^16531342785 is an apocalyptic number.

16531342785 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

16531342785 is a deficient number, since it is larger than the sum of its proper divisors (12857711295).

16531342785 is a wasteful number, since it uses less digits than its factorization.

16531342785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122454405 (or 122454399 counting only the distinct ones).

The product of its digits is 604800, while the sum is 45.

The spelling of 16531342785 in words is "sixteen billion, five hundred thirty-one million, three hundred forty-two thousand, seven hundred eighty-five".