997610881 has 16 divisors (see below), whose sum is σ = 1076431680. Its totient is φ = 921095680.

The previous prime is 997610863. The next prime is 997610899. The reversal of 997610881 is 188016799.

It is an interprime number because it is at equal distance from previous prime (997610863) and next prime (997610899).

It is a cyclic number.

It is not a de Polignac number, because 997610881 - 2⁵ = 997610849 is a prime.

It is a super-2 number, since 2×997610881² = 1990454939779192322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (997610851) 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, 762630 + ... + 763936.

It is an arithmetic number, because the mean of its divisors is an integer number (67276980).

Almost surely, 2^997610881 is an apocalyptic number.

It is an amenable number.

997610881 is a deficient number, since it is larger than the sum of its proper divisors (78820799).

997610881 is a wasteful number, since it uses less digits than its factorization.

997610881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2144.

The product of its (nonzero) digits is 217728, while the sum is 49.

The square root of 997610881 is about 31584.9787240707. The cubic root of 997610881 is about 999.2029919469.

The spelling of 997610881 in words is "nine hundred ninety-seven million, six hundred ten thousand, eight hundred eighty-one".