861965280 has 576 divisors, whose sum is σ = 3547333440. Its totient is φ = 194641920.

The previous prime is 861965257. The next prime is 861965303. The reversal of 861965280 is 82569168.

861965280 is a `hidden beast` number, since 8 + 619 + 6 + 5 + 28 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (861965257) and next prime (861965303).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 8886192 + ... + 8886288.

It is an arithmetic number, because the mean of its divisors is an integer number (6158565).

Almost surely, 2^861965280 is an apocalyptic number.

861965280 is a gapful number since it is divisible by the number (80) 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 861965280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1773666720).

861965280 is an abundant number, since it is smaller than the sum of its proper divisors (2685368160).

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

861965280 is a wasteful number, since it uses less digits than its factorization.

861965280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160 (or 135 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The square root of 861965280 is about 29359.2452219058. The cubic root of 861965280 is about 951.6923775986.

The spelling of 861965280 in words is "eight hundred sixty-one million, nine hundred sixty-five thousand, two hundred eighty".