861540090 has 32 divisors (see below), whose sum is σ = 2079133056. Its totient is φ = 228473280.

The previous prime is 861540089. The next prime is 861540103. The reversal of 861540090 is 90045168.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 73902 + ... + 84761.

It is an arithmetic number, because the mean of its divisors is an integer number (64972908).

Almost surely, 2^861540090 is an apocalyptic number.

861540090 is an abundant number, since it is smaller than the sum of its proper divisors (1217592966).

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

861540090 is a wasteful number, since it uses less digits than its factorization.

861540090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158854.

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 861540090 is about 29352.0031684381. The cubic root of 861540090 is about 951.5358683420.

The spelling of 861540090 in words is "eight hundred sixty-one million, five hundred forty thousand, ninety".