997566005081 has 4 divisors (see below), whose sum is σ = 1029745553664. Its totient is φ = 965386456500.

The previous prime is 997566005057. The next prime is 997566005099. The reversal of 997566005081 is 180500665799.

997566005081 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 997566005081 - 2³⁰ = 996492263257 is a prime.

It is a super-2 number, since 2×997566005081² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (997566008081) 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, 16089774245 + ... + 16089774306.

It is an arithmetic number, because the mean of its divisors is an integer number (257436388416).

Almost surely, 2^997566005081 is an apocalyptic number.

It is an amenable number.

997566005081 is a deficient number, since it is larger than the sum of its proper divisors (32179548583).

997566005081 is a wasteful number, since it uses less digits than its factorization.

997566005081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32179548582.

The product of its (nonzero) digits is 4082400, while the sum is 56.

The spelling of 997566005081 in words is "nine hundred ninety-seven billion, five hundred sixty-six million, five thousand, eighty-one".