100391280 has 120 divisors (see below), whose sum is σ = 342176016. Its totient is φ = 24330240.

The previous prime is 100391261. The next prime is 100391281. The reversal of 100391280 is 82193001.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 100391280.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100391281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27312 + ... + 30768.

Almost surely, 2^100391280 is an apocalyptic number.

100391280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 100391280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (171088008).

100391280 is an abundant number, since it is smaller than the sum of its proper divisors (241784736).

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

100391280 is a wasteful number, since it uses less digits than its factorization.

100391280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3495 (or 3478 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 100391280 is about 10019.5448998445. The cubic root of 100391280 is about 464.7634824468.

The spelling of 100391280 in words is "one hundred million, three hundred ninety-one thousand, two hundred eighty".