861399510 has 16 divisors (see below), whose sum is σ = 2067358896. Its totient is φ = 229706528.

The previous prime is 861399467. The next prime is 861399551. The reversal of 861399510 is 15993168.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14356629 + ... + 14356688.

It is an arithmetic number, because the mean of its divisors is an integer number (129209931).

Almost surely, 2^861399510 is an apocalyptic number.

861399510 is an abundant number, since it is smaller than the sum of its proper divisors (1205959386).

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

861399510 is a wasteful number, since it uses less digits than its factorization.

861399510 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28713327.

The product of its (nonzero) digits is 58320, while the sum is 42.

The square root of 861399510 is about 29349.6083449166. The cubic root of 861399510 is about 951.4841105692.

The spelling of 861399510 in words is "eight hundred sixty-one million, three hundred ninety-nine thousand, five hundred ten".