997991265 has 32 divisors (see below), whose sum is σ = 1637625600. Its totient is φ = 518819840.

The previous prime is 997991263. The next prime is 997991287. The reversal of 997991265 is 562199799.

It is not a de Polignac number, because 997991265 - 2¹ = 997991263 is a prime.

It is not an unprimeable number, because it can be changed into a prime (997991263) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 89521 + ... + 100049.

It is an arithmetic number, because the mean of its divisors is an integer number (51175800).

Almost surely, 2^997991265 is an apocalyptic number.

It is an amenable number.

997991265 is a deficient number, since it is larger than the sum of its proper divisors (639634335).

997991265 is a wasteful number, since it uses less digits than its factorization.

997991265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10697.

The product of its digits is 2755620, while the sum is 57.

The square root of 997991265 is about 31590.9997467633. Note that the first 3 decimals coincide. The cubic root of 997991265 is about 999.3299728305.

The spelling of 997991265 in words is "nine hundred ninety-seven million, nine hundred ninety-one thousand, two hundred sixty-five".