997809140 has 12 divisors (see below), whose sum is σ = 2095399236. Its totient is φ = 399123648.

The previous prime is 997809139. The next prime is 997809157. The reversal of 997809140 is 41908799.

It can be written as a sum of positive squares in 2 ways, for example, as 356605456 + 641203684 = 18884^2 + 25322^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24945209 + ... + 24945248.

It is an arithmetic number, because the mean of its divisors is an integer number (174616603).

Almost surely, 2^997809140 is an apocalyptic number.

It is an amenable number.

997809140 is an abundant number, since it is smaller than the sum of its proper divisors (1097590096).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

997809140 is a wasteful number, since it uses less digits than its factorization.

997809140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49890466 (or 49890464 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 47.

The square root of 997809140 is about 31588.1170695564. The cubic root of 997809140 is about 999.2691793646.

The spelling of 997809140 in words is "nine hundred ninety-seven million, eight hundred nine thousand, one hundred forty".