1809868690 has 64 divisors (see below), whose sum is σ = 3839768064. Its totient is φ = 601233408.

The previous prime is 1809868673. The next prime is 1809868729. The reversal of 1809868690 is 968689081.

It is a super-2 number, since 2×1809868690² = 6551249350084632200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (55) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 679842 + ... + 682498.

It is an arithmetic number, because the mean of its divisors is an integer number (59996376).

Almost surely, 2^1809868690 is an apocalyptic number.

1809868690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1809868690 is an abundant number, since it is smaller than the sum of its proper divisors (2029899374).

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

1809868690 is a wasteful number, since it uses less digits than its factorization.

1809868690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2971.

The product of its (nonzero) digits is 1492992, while the sum is 55.

The square root of 1809868690 is about 42542.5515219762. The cubic root of 1809868690 is about 1218.6594363036.

The spelling of 1809868690 in words is "one billion, eight hundred nine million, eight hundred sixty-eight thousand, six hundred ninety".