1025805665 has 16 divisors (see below), whose sum is σ = 1243756416. Its totient is φ = 812160000.

The previous prime is 1025805659. The next prime is 1025805667. The reversal of 1025805665 is 5665085201.

It is not a de Polignac number, because 1025805665 - 2⁶ = 1025805601 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1025805667) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 211265 + ... + 216065.

It is an arithmetic number, because the mean of its divisors is an integer number (77734776).

Almost surely, 2^1025805665 is an apocalyptic number.

It is an amenable number.

1025805665 is a deficient number, since it is larger than the sum of its proper divisors (217950751).

1025805665 is a wasteful number, since it uses less digits than its factorization.

1025805665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5240.

The product of its (nonzero) digits is 72000, while the sum is 38.

The square root of 1025805665 is about 32028.2010890403. The cubic root of 1025805665 is about 1008.5289387312.

The spelling of 1025805665 in words is "one billion, twenty-five million, eight hundred five thousand, six hundred sixty-five".