861540801 has 16 divisors (see below), whose sum is σ = 1254908928. Its totient is φ = 521413200.

The previous prime is 861540793. The next prime is 861540829. The reversal of 861540801 is 108045168.

It is not a de Polignac number, because 861540801 - 2³ = 861540793 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (861540851) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 6036 + ... + 41946.

It is an arithmetic number, because the mean of its divisors is an integer number (78431808).

Almost surely, 2^861540801 is an apocalyptic number.

It is an amenable number.

861540801 is a deficient number, since it is larger than the sum of its proper divisors (393368127).

861540801 is a wasteful number, since it uses less digits than its factorization.

861540801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36652.

The product of its (nonzero) digits is 7680, while the sum is 33.

The square root of 861540801 is about 29352.0152800451. The cubic root of 861540801 is about 951.5361300988.

Adding to 861540801 its reverse (108045168), we get a palindrome (969585969).

The spelling of 861540801 in words is "eight hundred sixty-one million, five hundred forty thousand, eight hundred one".