861947988 has 48 divisors (see below), whose sum is σ = 2198046144. Its totient is φ = 260720640.

The previous prime is 861947969. The next prime is 861948019. The reversal of 861947988 is 889749168.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70506 + ... + 81822.

It is an arithmetic number, because the mean of its divisors is an integer number (45792628).

Almost surely, 2^861947988 is an apocalyptic number.

It is an amenable number.

861947988 is an abundant number, since it is smaller than the sum of its proper divisors (1336098156).

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

861947988 is a wasteful number, since it uses less digits than its factorization.

861947988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11912 (or 11910 counting only the distinct ones).

The product of its digits is 6967296, while the sum is 60.

The square root of 861947988 is about 29358.9507305694. The cubic root of 861947988 is about 951.6860135470.

It can be divided in two parts, 861 and 947988, that added together give a palindrome (948849).

The spelling of 861947988 in words is "eight hundred sixty-one million, nine hundred forty-seven thousand, nine hundred eighty-eight".