16535909897 has 4 divisors (see below), whose sum is σ = 17807902980. Its totient is φ = 15263916816.

The previous prime is 16535909861. The next prime is 16535909899. The reversal of 16535909897 is 79890953561.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3986533321 + 12549376576 = 63139^2 + 112024^2 .

It is a cyclic number.

It is not a de Polignac number, because 16535909897 - 2⁶ = 16535909833 is a prime.

It is a super-2 number, since 2×16535909897² (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 (16535909899) 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, 635996522 + ... + 635996547.

It is an arithmetic number, because the mean of its divisors is an integer number (4451975745).

Almost surely, 2^16535909897 is an apocalyptic number.

It is an amenable number.

16535909897 is a deficient number, since it is larger than the sum of its proper divisors (1271993083).

16535909897 is a wasteful number, since it uses less digits than its factorization.

16535909897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1271993082.

The product of its (nonzero) digits is 18370800, while the sum is 62.

The spelling of 16535909897 in words is "sixteen billion, five hundred thirty-five million, nine hundred nine thousand, eight hundred ninety-seven".