997781232100 has 243 divisors, whose sum is σ = 2340448983579. Its totient is φ = 369189744000.

The previous prime is 997781232089. The next prime is 997781232103. The reversal of 997781232100 is 1232187799.

The square root of 997781232100 is 998890.

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 184234959076 + 813546273024 = 429226^2 + 901968^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (997781232103) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 9879022050 + ... + 9879022150.

Almost surely, 2^997781232100 is an apocalyptic number.

997781232100 is the 998890-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 997781232100

997781232100 is an abundant number, since it is smaller than the sum of its proper divisors (1342667751479).

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

997781232100 is a wasteful number, since it uses less digits than its factorization.

997781232100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348 (or 174 counting only the distinct ones).

The product of its (nonzero) digits is 381024, while the sum is 49.

Multiplying 997781232100 by its sum of digits (49), we get a square (48891280372900 = 6992230²).

It can be divided in two parts, 997781 and 232100, that added together give a square (1229881 = 1109²).

The spelling of 997781232100 in words is "nine hundred ninety-seven billion, seven hundred eighty-one million, two hundred thirty-two thousand, one hundred".