997951311 has 48 divisors (see below), whose sum is σ = 1682104320. Its totient is φ = 558331200.

The previous prime is 997951291. The next prime is 997951327. The reversal of 997951311 is 113159799.

It is a happy number.

It is not a de Polignac number, because 997951311 - 2²¹ = 995854159 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997951351) by changing a digit.

It is an upside-down number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1423261 + ... + 1423961.

It is an arithmetic number, because the mean of its divisors is an integer number (35043840).

Almost surely, 2^997951311 is an apocalyptic number.

997951311 is a deficient number, since it is larger than the sum of its proper divisors (684153009).

997951311 is a wasteful number, since it uses less digits than its factorization.

997951311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1156 (or 1153 counting only the distinct ones).

The product of its digits is 76545, while the sum is 45.

The square root of 997951311 is about 31590.3673767812. The cubic root of 997951311 is about 999.3166367878.

The spelling of 997951311 in words is "nine hundred ninety-seven million, nine hundred fifty-one thousand, three hundred eleven".