865773090 has 256 divisors, whose sum is σ = 2872074240. Its totient is φ = 180714240.

The previous prime is 865773079. The next prime is 865773091. The reversal of 865773090 is 90377568.

It is a happy number.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (865773091) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 4103085 + ... + 4103295.

It is an arithmetic number, because the mean of its divisors is an integer number (11219040).

Almost surely, 2^865773090 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 865773090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1436037120).

865773090 is an abundant number, since it is smaller than the sum of its proper divisors (2006301150).

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

865773090 is a wasteful number, since it uses less digits than its factorization.

865773090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414 (or 408 counting only the distinct ones).

The product of its (nonzero) digits is 317520, while the sum is 45.

The square root of 865773090 is about 29424.0223287028. The cubic root of 865773090 is about 953.0917149211.

The spelling of 865773090 in words is "eight hundred sixty-five million, seven hundred seventy-three thousand, ninety".