997719301881 has 27 divisors (see below), whose sum is σ = 1461482750637. Its totient is φ = 655890773760.

The previous prime is 997719301793. The next prime is 997719301907. The reversal of 997719301881 is 188103917799.

The square root of 997719301881 is 998859.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 10049060025 + 987670241856 = 100245^2 + 993816^2 .

It is a de Polignac number, because none of the positive numbers 2^k-997719301881 is a prime.

It is a super-2 number, since 2×997719301881² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (997719301981) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 218747841 + ... + 218752401.

Almost surely, 2^997719301881 is an apocalyptic number.

997719301881 is the 998859-th square number.

997719301881 is the 499430-th centered octagonal number.

It is an amenable number.

997719301881 is a deficient number, since it is larger than the sum of its proper divisors (463763448756).

997719301881 is an frugal number, since it uses more digits than its factorization.

997719301881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9274 (or 4637 counting only the distinct ones).

The product of its (nonzero) digits is 6858432, while the sum is 63.

It can be divided in two parts, 997719 and 301881, that added together give a square (1299600 = 1140²).

The spelling of 997719301881 in words is "nine hundred ninety-seven billion, seven hundred nineteen million, three hundred one thousand, eight hundred eighty-one".