1865400090 has 16 divisors (see below), whose sum is σ = 4476960288. Its totient is φ = 497440016.

The previous prime is 1865400041. The next prime is 1865400091. The reversal of 1865400090 is 900045681.

It is not an unprimeable number, because it can be changed into a prime (1865400091) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31089972 + ... + 31090031.

It is an arithmetic number, because the mean of its divisors is an integer number (279810018).

Almost surely, 2^1865400090 is an apocalyptic number.

1865400090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1865400090 is an abundant number, since it is smaller than the sum of its proper divisors (2611560198).

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

1865400090 is a wasteful number, since it uses less digits than its factorization.

1865400090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62180013.

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 1865400090 is about 43190.2777254326. The cubic root of 1865400090 is about 1230.9979540595.

The spelling of 1865400090 in words is "one billion, eight hundred sixty-five million, four hundred thousand, ninety".