1085640864 has 144 divisors (see below), whose sum is σ = 3616625376. Its totient is φ = 281971200.

The previous prime is 1085640847. The next prime is 1085640869. The reversal of 1085640864 is 4680465801.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1085640869) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 41254 + ... + 62234.

It is an arithmetic number, because the mean of its divisors is an integer number (25115454).

Almost surely, 2^1085640864 is an apocalyptic number.

1085640864 is a gapful number since it is divisible by the number (14) 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 1085640864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1808312688).

1085640864 is an abundant number, since it is smaller than the sum of its proper divisors (2530984512).

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

1085640864 is a wasteful number, since it uses less digits than its factorization.

1085640864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21019 (or 21004 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 42.

The square root of 1085640864 is about 32949.0646908224. The cubic root of 1085640864 is about 1027.7687156005.

The spelling of 1085640864 in words is "one billion, eighty-five million, six hundred forty thousand, eight hundred sixty-four".