999997555311609 has 4 divisors (see below), whose sum is σ = 1333330073748816. Its totient is φ = 666665036874404.

The previous prime is 999997555311529. The next prime is 999997555311611. The reversal of 999997555311609 is 906113555799999.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 999997555311609 - 2¹⁷ = 999997555180537 is a prime.

It is a super-2 number, since 2×999997555311609² (a number of 31 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (999997555311509) 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, 166666259218599 + ... + 166666259218604.

It is an arithmetic number, because the mean of its divisors is an integer number (333332518437204).

Almost surely, 2^{999997555311609} is an apocalyptic number.

It is an amenable number.

999997555311609 is a deficient number, since it is larger than the sum of its proper divisors (333332518437207).

999997555311609 is a wasteful number, since it uses less digits than its factorization.

999997555311609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333332518437206.

The product of its (nonzero) digits is 8370195750, while the sum is 87.

The spelling of 999997555311609 in words is "nine hundred ninety-nine trillion, nine hundred ninety-seven billion, five hundred fifty-five million, three hundred eleven thousand, six hundred nine".